Obama: Japan earthquake potentially 'catastrophic'

President Barack Obama pledged U.S. assistance to earthquake-ravaged Japan Friday following what he called a potentially "catastrophic" disaster.

"Our hearts go out to our friends in Japan and across the region, and we're going to stand with them as they recover and rebuild from this tragedy," Obama said during a White House news conference.

Obama said one U.S. aircraft carrier is already in Japan, and a second is on its way. A U.S. ship was also heading to the Marianas Islands to assist as needed, the president said.

Hundreds were dead or missing in Japan following Friday's 8.9 magnitude earthquake - the largest in Japan's history - and the accompanying tsunami.

Tsunami waves also swamped Hawaii's beaches and grazed the West Coast. Obama said that while there have been no reports of major damage in the U.S., his administration is taking the situation seriously and monitoring developments closely.

Obama urged residents in the affected areas to take warnings from local officials seriously and evacuate if told to do so.

THIS IS A BREAKING NEWS UPDATE. Check back soon for further information. AP's earlier story is below.

President Barack Obama says the earthquake and tsunami in Japan are a potentially "catastrophic" disaster, and he says his thoughts and prayers are with the Japanese people.

Speaking at a White House news conference, Obama says the U.S. is prepared to send whatever assistance Japan requests. He says one aircraft carrier is already in Japan and another is on its way.

Tsunami waves have also swamped Hawaii beaches and grazed the West Coast. Obama says that his administration is monitoring the impact of the tsunami on the U.S. closely. He told residents to take warnings from local officials seriously and evacuate if told to do so.

THIS IS A BREAKING NEWS UPDATE. Check back soon for further information. AP's earlier story is below.

The United States moved to send aid to earthquake-ravaged Japan Friday, as the first waves from the resulting tsunami swamped Hawaii beaches and grazed the West Coast.

President Barack Obama huddled with senior advisers at the White House to discuss plans to assist Japan, as well as the U.S. states and territories that could be affected. The Pentagon ordered a number of U.S. military ships to move toward Japan, preparing to render aid and bring supplies if needed.

Obama said in an early morning statement that his administration would "continue to closely monitor tsunamis around Japan and the Pacific going forward" and he directed FEMA to mobilize.

The largest earthquake in Japan's history - measured at a magnitude of 8.9 - pummeled the eastern coast of Japan Friday, accompanied by a towering tsunami. Hundreds were dead or missing.

FEMA administrator Craig Fugate said tsunami warnings and watches have been issued for the U.S. territories of Guam, the Northern Marianas Islands, and coastal areas in Hawaii, Alaska, California, Oregon and Washington.

Fugate urged people living in those areas to monitor their local news for instructions from their state and local officials, and evacuate if ordered to do so. And the Coast Guard said it was making preparations to provide support where necessary.

It said that Coast Guard cutter and aircraft crews were positioning themselves to be ready to conduct response and survey missions as soon as conditions allow.

Obama's chief of staff Bill Daley notified the president about the earthquake in Japan at 4 a.m. Washington time. Obama said the U.S. is ready to support the Japanese people "in this time of great trial."

"The friendship and alliance between our two nations is unshakeable," he said, "and only strengthens our resolve to stand with the people of Japan as they overcome this tragedy."

"Michelle and I send our deepest condolences to the people of Japan, particularly those who have lost loved ones in the earthquake and tsunamis," Obama's statement said.

The president was expected to discuss the situation in Japan and on the West Coast during a White House news conference early Friday afternoon. In advance of the news conference, Obama talked by telephone to Japanese Prime Minister Naoto Kan.

The Pentagon says the Japanese foreign minister has formally requested assistance from the United States in the wake of the massive earthquake and tsunami. Pentagon spokesman Col. David Lapan said U.S. and Japanese officials are talking constantly to determine what is needed, but it could include food, water, shelter, and medical supplies. The ships also have medical facilities to treat injured

Lapan said the military is also preparing to offer aid to Hawaii and the West Coast, if needed.

Janice Jacobs, assistant secretary of state for consular affairs, told reporters on a conference call Friday that there have been no reports of Americans killed or injured in Japan. There were also no reports of damage to U.S. installations or ships in the area.

The State Department issued a travel alert, strongly urging U.S. citizens to avoid non-essential travel to Japan.

"Tokyo airports are currently closed," it said. "Other airports in Japan may be closed or have restricted access. Public transportation, including trains and subways, are closed in the Tokyo area, and service has been interrupted in many other areas."

"Strong aftershocks are likely for weeks," the department said. It urged U.S. citizens currently in Japan to "contact family and friends in the United States to confirm their well-being at the earliest opportunity."

Spokesman P.J. Crowley tweeted early Friday that ambassador John Roos "has moved our U.S. Embassy's command center to an alternate location as a precaution, given the many aftershocks in Tokyo."

"We have been watching a hopeful tsunami sweep across the Middle East. Now we are seeing a tsunami of a different kind sweep across Japan," Crowley said.

At home, FEMA's Fugate said that "our immediate priority is the safety of the people and communities in the affected areas."

"FEMA is closely monitoring the affects of the earthquake and subsequent tsunami that struck Japan," he said, "and through our regional offices in the West Coast and the Pacific area, we are in close contact and coordination with state and local officials and stand ready to support them in any way needed."

The Navy said Friday that the aircraft carrier USS Ronald Reagan, which was in the Western Pacific, was preparing to respond if asked, and was moving toward Japan.

There were no reports of damage to the aircraft carrier USS George Washington, which was in port in Japan. In Guam, the mooring lines of two US navy submarines broke free of the pier, but there was no damage and the ships were pushed back by tugs.

No ships have been moved as a result of the potential tsunami in Hawaii.

Vice President Joe Biden, making a joint appearance at a news conference in Chisinau, Moldova Friday with Prime Minister Vlad Filat, said "the thoughts and prayers of the American people" are with the Japanese, who he said had suffered through a "mega earthquake."

"We, the United States, stand ready to do anything we can to help our Japanese friends as they deal with the aftermath of this tragedy," Biden said.