Paraguay and the United States bilateral diplomacy began amid regional tensions and an 1855 episode of hostility that claimed one life. The encounter led to the establishment of formal ties and set the tone for more than two centuries of relations that have expanded into cooperation on issues of geopolitics, trade, economic development, and cultural exchange. The two nations maintain embassies in each other's capitals and generally enjoy friendly relations centered on democratic governance and regional stability.
According to Gallup’s Rating World Leaders 2024 survey, 42 percent of Paraguayans approve of U.S. leadership, while 28 percent disapprove and 30 percent express no opinion. The findings represent a 15-percentage-point drop in approval from the previous year. While the reason for this approval decrease is uncertain, intergovernmental tensions rose during the presidency of Joe Biden after the United States applied sanctions on Horacio Cartes, the billionaire leader of the ruling Colorado Party, who served as Paraguay's president from 2013 to 2018.
Paraguay formally requested the early departure of U.S. Ambassador Marc Ostfield in August 2024 following new sanctions on Cartes’s tobacco company, but Ostfield did not leave his post until the Biden–Donald Trump presidential transition. The Trump administration lifted sanctions on Cartes in October 2025, a move welcomed by President Santiago Peña. In granting Cartes sanctions relief, the State Department said the sanctions were “no longer required to incentivize changes in behavior,” though accusations persist that Cartes has bribed legislators and exerted undue influence within Peña’s government. The Paraguayan government described the measures as politically motivated and harmful to national industry; Peña's administration said their suspension represented the end of U.S. "persecution." Peña has sought close ties with Trump since his return to office, describing him as a “friend of Paraguay.”
Despite this détente, the ambassadorship has remained vacant for more than 20 months, about three and a half times the historical average for this office among previous U.S. administrations. In June 2026, Trump nominated Ohio agriculture businessman Paul Kalmbach as Ostfield's successor, but the United States Senate later adjourned until November ahead of the 2026 midterms, having taken no action on Kalmbach. During this time, Paraguay has dispatched two ambassadors to Washington, including incumbent Estefania Laterza de los Rios.
History • 19th century • 20th century • 21st century • Socioeconomic relations • Trade • Travel • Cultural exchange • Resident diplomatic missions
History 19th century Following its independence in 1811, Paraguay practiced strategic isolation from the outside world, maintaining little to no contact with the United States for nearly four decades. The U.S. recognized Paraguay’s independence on April 27, 1852.
Over the following century, Paraguay twice waged full-scale wars with neighboring states, amid which the United States participated in peace negotiations and post-war boundary settlements. Both world wars of the 20th century had limited impact on U.S.–Paraguay relations, but during the Cold War the United States expanded its involvement in South America to counter Soviet influence. Since that period, bilateral engagement has focused primarily on supporting free and fair elections, discouraging corruption, and strengthening economic cooperation.
The Water Witch incident President Carlos Antonio López, first Paraguayan to hold that title, signed several treaties of friendship, commerce, and navigation with world powers in the 1850s. López mistrusted his Latin American neighbors and sought more distant foreign ties to strengthen Paraguay’s nascent economy and defenses. The U.S. engaged in a form of "gunboat diplomacy" in this early period: Paraguayan troops at Fort Itapirú, near the junction of the Paraguay and Paraná rivers, opened fire on the survey steamer Water Witch on February 1, 1855. The Water Witch had been dispatched from Buenos Aires to map potential trade routes in South America. President Carlos Antonio López ordered the shelling out of fear that the vessel sailed under false pretenses to conduct espionage; he also sought to assert Paraguayan sovereignty.
Samuel Chaney, a Water Witch helmsman, died instantly after a direct hit by cannon fire. Commanding officer Thomas J. Page recorded no other casualties in his dispatch to Washington. President Franklin Pierce sent a note of protest to López but took no further action. James Buchanan succeeded as U.S. president in 1857 and, after extended preparations, ordered 19 ships carrying some 2,500 U.S. servicemen to sail to Asunción and demand accountability. Paraguay expressed conciliation after the force's arrival in January 1859. López's government paid an indemnity of $10,000 (about $395,000 in 2025) for Chaney's death as part of a new treaty of friendship, commerce, and navigation. The payment served as a mostly symbolic gesture, as the United States expended well over $2 million (more than $70 million in 2025) to fund the expedition.
Although the American Civil War curtailed U.S. diplomatic engagement in Latin America, President Abraham Lincoln dispatched Charles Ames Washburn to Paraguay in 1861 as U.S. commissioner; Washburn later served with the rank of minister resident. Francisco Solano López, who succeeded his father as Paraguay’s leader in 1862, expelled Washburn in 1868. While Washburn expressed sympathy for Paraguay’s position in its conflicts with neighboring states, López accused him of abusing diplomatic asylum by harboring dissidents at the U.S. mission. Martin T. McMahon arrived in 1869 as the second senior U.S. diplomat to reside in Paraguay.
South America's bloodiest conflict The War of the Triple Alliance (1864–1870) against Brazil, Argentina, and Uruguay devastated Paraguay for generations. During his tenure as minister resident, McMahon urged for the U.S. to intervene in the War of the Triple Alliance, having witnessed firsthand the grievous harm it inflicted. By some estimates, as much as half of Paraguay’s prewar population — likely between 400,000 and 500,000 people — had died by the time Brazil, Argentina, and Uruguay ended their occupation in the mid-1870s.
The United States regarded victorious Brazil and Emperor Pedro II with particular disfavor. Brazil retained slavery for decades after the U.S. abolished it, and anti-monarchism extant since the end of British rule in the U.S. remained popular. Pedro II also welcomed immigrants to Brazil who remained bitter over the Confederates’ defeat in the American Civil War, and who wished to continue owning slaves. Brazil sustained heavy casualties and expenditures to invade Paraguay, but finished the effort with a battle-hardened, professional army that challenged U.S. strategic ambitions in the Americas. McMahon described the war in Paraguay as an “extermination” by the allied powers and invoked the Monroe Doctrine as justification for the United States to help end the bloodshed and restrain imperial expansion in South America. Using his influence as a senior officer and veteran of the American Civil War, McMahon won sympathetic press coverage and informal hearings in Washington. Nevertheless, President Ulysses S. Grant declined to pursue any diplomatic, economic, or military measures in Paraguay’s favor, wary of foreign entanglements in the Reconstruction era.
In the war’s aftermath, Paraguay and Argentina had ongoing border disputes. Both nations submitted the matter to arbitration by Rutherford B. Hayes, U.S. president from 1877 to 1881, who granted Paraguay most of the contested territory in 1878. Paraguay later named a city, an administrative region, and a national holiday in his honor; it observes November 12 as Día del Laudo Hayes, commemorating the award that preserved its sovereignty.
20th century After the war's conclusion, Paraguay received little international attention until the Chaco War with Bolivia (1932–1935). U.S. and European firms supplied arms to both sides. Populist politician Huey Long promoted Paraguay's cause on the floor of the U.S. Senate and derided Bolivia, shifting public perception of the war in the U.S. and in Latin America. A peace treaty in 1938 involving U.S. and other neutral diplomats awarded most of the Chaco region to Paraguay.
U.S. engages with dictators Washington's influence in Paraguay expanded during World War II with economic and technical assistance.Paraguay – World War II and Aftermath, U.S. Library of Congress Country Studies. Retrieved 10 October 2025. Seeking to counter Axis influence in South America, in 1942 the U.S. funded significant public health, agriculture and infrastructure projects in Paraguay for the first time. During the conflict, Washington liaised with Higinio Morínigo, a general who seized the Paraguayan presidency in 1940. Morínigo, having no ideological opposition to fascism, severed ties with Nazi Germany and its allies in 1942 under pressure from the United States and in pursuit of economic aid. For the same reasons, he declared war on the Axis in February 1945. With the war in Europe nearly over by that time, Paraguayan forces never saw combat abroad. Beyond the country’s limited resources and landlocked geography, Paraguayans expressed reluctance to enter another conflict after suffering more than 50,000 killed and wounded in the Chaco War.
In the post-war period, Paraguay experienced several years of political instability. Morínigo lost power and fled to exile in Argentina in 1948, and several men served as president for brief periods before Alfredo Stroessner established a new dictatorship in 1954. During his 35-year rule, the United States supported anti-communist repression and maintained close security and economic ties.Peter Kornbluh, The Condor Years: How Pinochet and His Allies Brought Terror to Three Continents (New York: The New Press, 2004), pp. 249–252. Between 1962 and 1989, the United States provided more than $150 million in direct economic and military assistance to the Stroessner regime. The United States indirectly supported the Itaipu Dam, inaugurated in May 1984 by Stroessner and his Brazilian counterpart, the dictator João Figueiredo. More than $2 billion in U.S. aid for Brazil as a whole arrived during this era under the Alliance for Progress, helping to strengthen Brazil's financial and energy sectors and enabling financing for Paraguay's share of Itaipu’s construction.
The restoration of democracy