US officials suspected Yemen had stocks of shoulder-fired missiles, a major concern if they fell in the wrong hands, while the Yemeni leader sought to use newfound leverage for US aid, secret memos said.

Although Yemen's Defense Ministry insisted it had no such cache of the weapons, an informant told US diplomats that the government agency in fact "does indeed have MANPADS, but would never speak of them because they are considered a state secret."

The embassy cable marked "secret" and dated August 4, 2009 also said that while Yemen "realizes their MANPADS are of little military value, they consider them better than nothing and would turn them over for destruction only if they were able to get a modern air defense system in return."

Man Portable Air Defense Systems (MANPADS) are shoulder-fired missiles designed to down aircraft, and were most famously used by Afghan fighters in the 1980s to shoot down helicopters and eventually drive out Soviet forces.

The cable was published by The New York Times as part of the release of over 250,000 State Department memos, most from the last three years, by whistleblower website WikiLeaks.

Yemeni President Ali Abdullah Saleh meanwhile revelled in the attention he received from US officials as Al-Qaeda's branch in Yemen and its suspected US-born leader Anwar al-Awlaqi brought renewed scrutiny and worries about his country's instability.

Saleh said that while he was "satisfied" with US military aid, he "would like to be more satisfied in the future," according to an account of the meeting sent to Washington.

Weeks after a young Nigerian tried, and failed, to blow up an airliner filled with passengers as it approached Detroit on Christmas Day last year, Saleh was keen to use his influence to chide American officials.

The Americans are "hot-blooded and hasty when you need us," he told a visiting State Department counterterrorism chief Daniel Benjamin on January 31, but "cold-blooded and British when we need you."

At other times, Saleh used his country's travails as a kind of threat to visiting US envoys.

"Referencing the high poverty rate and illicit arms flows into both Yemen and Somalia, Saleh concluded by saying, 'If you don't help, this country will become worse than Somalia,'" according to a September 2009 cable from US ambassador Stephen Sech.

The National Security Bureau (NSB), a Yemeni intelligence agency close to the United States, was also convinced the stocks of shoulder-fired missiles existed.

But one of the US diplomats who drafted the memo was not so sure, writing: "It is hard to know what to believe regarding the presence or absence of MoD (Ministry of Defense) MANPADS."

In the end, US diplomats decided to continue negotiating with the NSB over the destruction of the MANPADS, since the defense ministry "appears unwilling to discuss the issue with (US) officials directly."

The cable noted that since 2004, the two governments had "dramatically reduced" the availability of such weapons on the black market in Yemen, a deeply tribal country where the government's power is limited.

Yemen is currently battling Al-Qaeda in the Arabian Peninsula (AQAP), an offshoot of Osama bin Laden's global network that has engineered at least two failed attacks on the United States in the last year.

Shoulder-fired missiles have already been used by Al-Qaeda in Kenya, Saudi Arabia and Yemen in 2001 and 2002, according to the cable.