LA GUAIRA, Venezuela— Russian President Dmitry Medvedev agreed to help start a nuclear energy program in Venezuela and said Moscow is willing to participate in a socialist trade bloc in Latin America led by President Hugo Chavez.

Medvedev used his visit to Venezuela—the first by a Russian president— to extend Moscow’s reach into Latin America and deepen trade and military ties. Chavez denied trying to provoke the United States, but he welcomed Russia’s growing presence in Latin America as a reflection of declining U.S. influence.

Chavez saluted the ship’s captain, and while touring the vessel with Medvedev joked to reporters from the deck: “We’re going to Cuba!” While aboard the destroyer, Venezuelan officials signed a deal to buy two Russian-made Ilyushin Il-96 passenger jets to add to the state airline’s fleet for long-range flights. Moscow plans to develop a nuclear cooperation program with Venezuela by the end of next year, said Sergei Kiriyenko, head of the Russian Federal Atomic Energy Agency.