BOGOTA, COLOMBIA - Russia delivered at least 1,800 shoulder-fired antiaircraft missiles to Venezuela in 2009, U.N. arms control data show, despite vigorous U.S. efforts to stop President Hugo Chavez's stridently anti-American government from acquiring the weapons.

The United States feared that the missiles could be funneled to Marxist guerrillas fighting Colombia's pro-American government or Mexican drug cartels, concerns expressed in U.S. diplomatic cables obtained by WikiLeaks and first reported in the Spanish newspaper El Pais.

It had been unclear how many of the Russian SA-24 missiles were delivered to Venezuela, though the transfer itself was not secret. Chavez showed off a few dozen at a military parade in April 2009, saying they could "deter whatever aerial aggression against our country." A high-level Russian delegation told American officials in Washington in July of that year that 100 of the missiles had been delivered in the first quarter of 2009.

Then earlier this year, Russia reported to the U.N. Register of Conventional Arms, which records the transnational sale of weaponry, that the deal totaled 1,800 missiles.

The U.N. registry did not reveal the model of the delivered weaponry. But the American commander for military forces in Latin America, Air Force Gen. Douglas Fraser, publicly expressed concern this year that Venezuela was purchasing as many as 2,400 of the missiles.

Matt Schroeder, a missile expert at the Federation of American Scientists in Washington, said the missiles are among the most sophisticated in the world and can down aircraft from 19,000 feet.

"It's the largest recorded transfer in the U.N. arms registry database in five years, at least. There's no state in Latin America of greater concern regarding leakage that has purchased so many missiles," he said, referring to reports of Venezuelan arms flowing to Colombian guerrillas.

The database also shows that from 2006 through 2008, Russia delivered to Venezuela 472 missiles and launching mechanisms, 44 attack helicopters and 24 combat aircraft, purchases funded by Venezuelan oil sales.

A self-styled Socialist who claims that successive U.S. governments want to topple him, Chavez told his countrymen during the 2009 military parade that "we don't want war with anyone, but we are obligated to prepare." Months later, in December 2009, he said in a nationally televised address that "thousands of missiles are arriving" but did not say what kind.

Secret American cables said that the United States was concerned about the Chavez government's acquisition of Russian arms, which also included attack helicopters, Sukhoi fighter planes and 100,000 Kalashnikov assault rifles.

A State Department cable on Aug. 10, 2009, to embassies in Europe and South America said Russian sales to Venezuela total "over $5 billion last year and growing." There was also concern about Spain's plans to sell aircraft and coastal patrol boats to Venezuela.

The cables show how both the Bush and Obama administrations tried to stop the arms sales by highlighting the possibility that the weapons could end up with the Revolutionary Armed Forces of Colombia, or FARC, a rebel group that Colombian officials say has received material support from Chavez's government.