President Bush was briefed by staff on a 8.7-scale earthquake near Indonesia (search) as American diplomatic, geological and oceanic officials moved swiftly Monday to provide aid and planning assistance.

Aides gave the president details of the quake as he flew back to Washington after spending Easter week at his ranch in Texas, a White House official said.

"The president has been briefed on the earthquake and we are monitoring the situation," White House spokeswoman Dana Perino told reporters aboard Air Force One.

More than 174,000 people were killed and a million and a half more were left homeless following the Dec. 26 Indian Ocean tsunami. Congress approved nearly $1 billion in aide and former Presidents Bill Clinton (search) and George H.W. Bush (search) were appointed to lead a fund-raising effort among Americans that collected another $1 billion.

Despite the donations, nations in the ravaged areas and elsewhere criticized U.S. agencies for not providing better warning of the impending waves. The United States does not have tsunami (search) warning systems outside its own risk areas.

Nonetheless, State Department spokesman Adam Ereli told reporters that in the wake of the last disaster, several nations have been planning to put in place an international tsunami warning system, with a meeting most recently being held in Tokyo. In the meantime, the Pacific Tsunami Warning Center is monitoring the situation, Ereli said, and U.S. officials abroad are on alert to help out where they can.

"Where we are right now is having alerted all our posts, been in contact with all our posts, putting ourselves in battle mode to be in a position where we can know what's going on and act appropriately if and when it's necessary," he said. "We are communicating to our embassies in the affected areas about the event and encouraging them to work closely with host governments and local aid agencies to be responsive."

The U.S. Geological Survey (search) has moved to provide details via the Internet. The Pacific Tsunami Warning Center (search), an agency of the National Oceanic and Atmospheric Administration (search), issued a bulletin shortly after the earthquake that anyone within 600 miles of the epicenter of Monday's earthquake should evacuate to higher ground since the quake has the potential to create a devastating wave.

The center does not have tide gauges in the Indian Ocean and said it does not know whether a wave was generated, but said the quake "has the potential to generate a widely destructive tsunami in the ocean or seas."

Pat McCrummen, a spokesman for the American Red Cross (search) in Washington, said the agency confirmed that its workers involved in the relief effort in Indonesia were OK following the latest earthquake. He said Red Cross officials are awaiting further developments before initiating any new relief effort.

"We still have people over there assisting from the first one, and they will be our first line of defense, once we know what kind of damage there is," he said.

The Associated Press contributed to this report.