Obama Says Qaida 'Hammered' but Terror Threat Real

President Barack Obama insisted Wednesday that al-Qaida's leaders were on the ropes, but admitted the threats that have closed U.S. embassies across the Middle East must be taken seriously.

His remarks to around 3,000 Marines at Camp Pendleton military base in California came after around 20 U.S. missions were shut in response to intelligence reports that an attack on U.S. interests could be imminent.

"Because of you, al-Qaida's top ranks have been hammered," the U.S. president told the troops. "The core of al-Qaida in Afghanistan and Pakistan is on the way to defeat. That happened because of you."

But, turning to the current threat, Obama said information about a possible act of terror would have to be scrutinized and dealt with.

"The end of the war in Afghanistan doesn't mean the end of threats to our nation. We've been reminded of this again in recent days.

"So I want to take a special time out to salute all our brave diplomats and tireless intelligence and military personnel who have been working around the clock to safeguard our embassies and our consulates and our fellow Americans serving overseas."

Following the embassy closures, Yemen said Wednesday it had foiled an al-Qaida plot to storm a Western-run oil terminal and seize a provincial capital. The United States has pulled diplomatic staff out of Yemen.

Obama said "extremists" would not halt U.S. policy overseas.

"Here's what those who would cowardly attack our civilians don't get: The United States is never going to retreat from the world," he said.

"We don't get terrorized. We're going to keep standing up for our interests."