U.S. Defense Secretary Robert Gates said Sunday that the U.S. State Department, in tandem with other countries, has been conducting preliminary "outreach" talks with the Taliban in Afghanistan.

"I think there's been outreach on the part of a number of countries, including the United States," Gates told CNN.

Police blocked off roads around the Pentagon on Friday and searched the surrounding area after arresting a man with a suspicious backpack in nearby Arlington National Cemetery.

Police later identified the suspect as 22-year-old Marine Corps reservist Yonathan Melaku.

The United States is stepping up contacts inside and outside Syria with Syrians who are seeking political change, a State Department spokeswoman said Thursday.

The move appeared to mark a toughening in the administration's stance toward Damascus as it escalates an internal crackdown on dissent with military sweeps on towns near the Turkish border.

The United States Thursday dismissed new al-Qaida supremo Ayman al-Zawahiri as a pale imitation of Osama bin Laden and warned the Egyptian to expect a similar fate to his slain predecessor.

U.S. officials painted the 59-year-old long-time number two as an "armchair general" with no combat experience, saying he not only lacked charisma and leadership skills but was also a divisive figure who could fracture al-Qaida.

The U.S. Senate Armed Services Committee unanimously approved Leon Panetta's nomination to be US defense secretary on Tuesday, setting the stage for a full senate confirmation.

Panetta, 72, who has served President Barack Obama as CIA chief, was expected to sail to confirmation by the full U.S. Senate, though the precise timing of a final vote was not yet clear.

U.S. Secretary of State Hillary Clinton on Tuesday accused Iran of backing Syrian President Bashar al-Assad's "vicious assaults" against pro-democracy protesters.

"Iran is supporting the Assad regime’s vicious assaults on peaceful protesters and military actions against its own cities," Clinton said, comparing its response to Iran's crackdown on pro-reform protests in 2009.

Republican presidential candidates led by frontrunner Mitt Romney used their first big televised debate to lash out at President Barack Obama -- but not each other.

The debate in Manchester, New Hampshire, late Monday did little to define differences between the seven candidates in the unwieldy Republican line-up as White House hopefuls reserved their venom for Obama on the economy and foreign policy.

France on Tuesday urged Lebanon's new government to honor its international commitments, including maintaining support for the U.N.-backed Special Tribunal for Lebanon.

"The formation of the Lebanese government ... is an important step for Lebanon and the Lebanese," the French foreign ministry said in a statement, referring to a new cabinet dominated by Hizbullah and its allies.

The United States said Monday it would judge the new Lebanese government "by its actions" following the announcement of a 30-member cabinet dominated by Hizbullah and its allies.

"We'll judge it by its actions," U.S. State Department spokesman Mark Toner said.

Libya's embattled leader Moammar Gadhafi appears to have written to the U.S. Congress to praise its criticism of President Barack Obama over NATO raids on Libya, officials said Friday.

In the letter seen by Agence France Presse, Gadhafi comments on growing debate in Congress over whether Obama has usurped his constitutional authority by committing U.S. forces to the conflict without authorization by lawmakers.