President Obama met Tuesday with his top advisers

U.S. President Barack Obama met Tuesday with his top advisers about the situation on the Korean peninsula, in the wake of North Korea's artillery attack on a South Korean island. Obama is expected to telephone South Korean President Lee Myung-bak to reiterate U.S. support for South Korea.Immediately upon his return to the White House from a brief trip to the Midwestern state of Indiana, the president went into a meeting  of his national security team.

According to a White House statement, National Security Advisor Tom Donilon, and Secretaries of State and Defense Hillary Clinton and Robert Gates were among those taking part.



U.S. envoy for North Korea Stephen Bosworth was in Beijing, consulting South Korean, Japanese and Chinese officials, and is expected to meet with the president. The key focus of Bosworth's talks in the region was Pyongyang's recent revelation of an apparent uranium enrichment plant.

Bosworth called the North Korean artillery attack that killed two South Korean marines and wounded 18 people, three of them civilians, "aggression."

The U.S. State Department on Tuesday called the attack an "unprovoked military assault," and said the Obama administration is planning a "measured and unified" response, working with China and other nations in the six-party talks on North Korea's nuclear program.