When Venezuelan President Hugo Chavez went on a military shopping spree in Russia -- mostly on extended credit -- he argued in public rhetoric he feared a joint Colombian-U.S. invasion aimed at removing his populist regime.

Leaked diplomatic papers say the United States, far from planning to invade Venezuela, fretted over the missile buying program and tried to dissuade Moscow from going ahead with the deliveries.

U.S. diplomats argued against any Russian deliveries on the missile deal, reached in 2009, because they feared the weapons could end up with FARC rebels in Colombia or even in the organized crime ranks of Mexican drug warlords.

Diplomatic cables given to WikiLeaks, which released them to various media outlets, said Venezuela may have received at least 1,800 of the SA-24 shoulder-fired missiles from Russia. The Washington Post cited U.N. arms control data on the reported delivery.

Nor were U.S. concerns limited to deliveries of the missiles. Leaked U.S. cables said Washington was concerned about Venezuela acquiring combat helicopters, Russian Sukhoi fighter jets and 100,000 Kalashnikov rifles.

Venezuela and U.S. diplomats are locked in a row over Caracas's refusal of designated U.S. Ambassador Larry Palmer after Chavez took exception to Palmer's leaked comments on his government.

The leaked cables cited reports that Russian arms sales totaled more than $5 billion in August 2009 and could be on the rise. Diplomats also expressed concerns that EU member Spain was on the verge of becoming a major arms supplier to Venezuela, with plans afoot to provide the Latin American country with aircraft and patrol boats.

There has been no follow-up to the reported Spanish arms sales to Venezuela but the Post said the U.N. Register of Conventional Arms showed the Russian deal totaled 1,800 missiles.

U.S. Air Force Gen. Douglas Fraser said this year Venezuela could be buying as many as 2,400 of the missiles, the newspaper said.

Federation of American Scientists arms expert Matt Schroeder told the Post the Russian missiles are among the world's most sophisticated offensive projectiles and can bring 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," Schroeder told the Post, in a reference to allegations that Venezuela regularly passes on weapons to FARC guerrillas fighting Colombia.

Caracas has consistently denied reports it aids the guerrillas. FARC is accused by Colombia and U.S. security officials of being involved with the drug gangs that operate the narcotics trail to North America.

An August 2009 U.S. diplomatic cable noted Russian ammunition sold to Venezuela was found in FARC guerrilla ranks and U.S. officials raised the issue with Russian diplomats in Washington, the Post reported.