NATO Secretary General Anders Fogh Rasmussen on Friday welcomed a "clear" U.S. statement accusing the Syrian regime of using chemical weapons and said Damascus must let the U.N. investigate the allegations.

"I welcome clear U.S. statement. Urgent that Syria regime should let U.N. investigate all reports of chemical weapons use," he said on his official Twitter feed.

President Barack Obama has authorized sending weapons to Syrian rebels for the first time, U.S. officials said Thursday, after the White House disclosed that the United States has conclusive evidence President Bashar Assad's government used chemical weapons against opposition forces trying to overthrow him.

Obama has repeatedly said the use of chemical weapons would cross a "red line," suggesting it would trigger greater American intervention in the two-year crisis.

A gunman who killed four people in a shooting and carjacking rampage was a former student at the California college where he was ultimately killed by police, officials said at a press conference Saturday.

Santa Monica Police Chief Jacqueline Seabrooks said the gunman, whose name she did not release, was armed with some 1,300 rounds of ammunition and an arsenal of weapons during Friday's bloody killing spree.

Throwing formality aside at a desert retreat, the U.S. and Chinese leaders pledged a new approach in ties, but President Barack Obama took the rising power to task on cyber-hacking charges.

Skipping the usual summit pageantry, Obama and Chinese President Xi Jinping both went without neckties at a resort under the blazing California sun as they looked to forge a personal chemistry for the years to come.

U.S. Republican senator John McCain warned on Thursday that the more than two-year-old war in Syria was reopening confessional wounds in Lebanon and said thousands of Hizbullah fighters were operating in the country.

“Old sectarian wounds are being reopened in Lebanon,” McCain said.

President Barack Obama will name U.N. ambassador Susan Rice as his new national security adviser Wednesday, months after the Benghazi affair scuppered her hopes of becoming the top U.S. diplomat.

Rice will take over from Obama's current national security adviser Tom Donilon in July, in a shake-up of his foreign policy team that will see former aide and genocide expert Samantha Power take the top United Nations job.

NATO is sending a team to Libya to look at the possibility of training its military, alliance head Anders Fogh Rasmussen said Tuesday, some two years after NATO helped rebels oust Moammar Gadhafi.

The team will be sent as soon as possible and return by the end of June when the next step will be determined, Rasmussen said.

Turning the screw on Iran and its nuclear program, the Obama administration imposed new sanctions Monday on Iran's currency and auto industry, seeking to render Iranian money useless outside the country and to cut off the regime from critical revenue sources.

The executive order from President Barack Obama broadens what is already a concerted and multifaceted sanctions campaign aimed at crippling Iran's economy, forcing it to comply with international demands that it prove its nuclear program is peaceful. The U.S. believes Iran is working to develop nuclear weapons, a charge that Iran denies.

U.S. lawmakers and activists called Monday on President Barack Obama to speak firmly on human rights when he meets his Chinese counterpart, 24 years after Beijing crushed protests in Tiananmen Square.

President Xi Jinping heads to California on Friday for his first talks with Obama since assuming office in Beijing, with alleged Chinese support for cyber attacks on U.S. companies and government set to be high on the agenda.

U.S. President Barack Obama said Friday that NATO will hold a summit next year on the "final chapter" in its Afghan war and on a new training mission for after combat troops withdraw at the end of 2014.

Obama made the announcement as he met NATO Secretary General Anders Fogh Rasmussen for White House talks, also focusing on modernizing the alliance's forces and the need to stabilize Libya's borders.