"FEMA is closely monitoring the affects of the earthquake and subsequent tsunami that struck Japan early this morning, and through our regional offices in the West Coast and in 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. Our thoughts and prayers go out to those affected by this tragedy.
"Tsunami warnings and watches have been issued for the U.S.
territories of Guam, the Commonwealth of the Northern Marianas Islands, as well as portions of coastal areas in Hawaii, Alaska, California, Oregon and Washington.
"Our immediate priority is the safety of the people and communities in the affected areas. We remind everyone who lives in the region to monitor their local news for instructions from their state and local officials and if told to evacuate - evacuate."
The United States says it is prepared to immediately offer Japan whatever assistance it might need in the wake of Friday?s massive earthquake. Secretary of State Hillary Clinton says the United States has flown coolant to a threatened Japanese nuclear power plant.
What amounts to an open-ended U.S. offer of assistance to its key Asian ally, Japan, was conveyed in a telephone call by President Barack Obama to Japanese Prime Minister Naoto Kan.
The State Department said the United States stands ready to provide Japan with whatever help might be needed to deal with what has been described as that country?s most serious earthquake in modern times.
At a White House business conference, Secretary of State Clinton said the United States has already responded by airlifting coolant to a nuclear power plant in northern Japan believed to be in jeopardy after a systems failure.
"You know Japan is very reliant on nuclear power and they have very high engineering standards," said Clinton. "But one of their plants came under a lot of stress with the earthquake and didn?t have enough coolant. So [U.S.] Air Force planes were able to deliver that. So we?re really deeply involved in trying to do as much as we can on behalf of the Japanese and on behalf of U.S. citizens."
Japan declared an emergency and evacuated an area around the Fukushima power plant, though officials later said the situation was under control and the reactor cooling system was operating under a back-up system.
In a written statement, Secretary Clinton said the United States is an "unwavering friend and ally" of Japan and is committed to helping it respond to and recover from the disaster.
State Department officials said U.S. ambassador to Japan John Roos had spoken to Foreign Minister Takeaki Matsumoto to also convey an offer assistance, but that there has not yet been a specific response.
The State Department issued a travel alert advising Americans to avoid tourism and non-essential travel to Japan, while also providing practical advice to Americans already there about how to respond to potential aftershocks.
Assistant Secretary of State for Consular Affairs Janice Jacobs said many thousands of U.S. citizens either reside in or are visiting Japan at any one time, but that there have been no early reports of any American casualties.
The State Department has set up a 24-hour task force of officials to help concerned Americans account for relatives and friends in Japan.
It recommended that with telephone service in Japan disrupted, Americans might try using Internet media such as Twitter and Facebook to contact friends and family members there.