Barack Obama will act quickly to engage in diplomatic efforts around the world after he officially becomes the next U.S. president on Tuesday, according to a top aide.

David Axelrod told CNN's State of the Union on Sunday that while the faltering economy is Obama's No. 1 priority, he doesn't want to waste any time attending to foreign affairs.

"The president-elect has said repeatedly that he intends to engage early and aggressively with diplomacy all over the world, and using the men and women, the professionals who are in place, who are great — and where appropriate, the special envoys," Axelrod said.

"I think events around the world demand that he act quickly and I think you'll see him act quickly," he added.

Axelrod did not provide details for what Obama plans to do about the Middle East.

On Saturday, Israel declared a unilateral ceasefire in its military operations against Hamas militants in the Gaza Strip and urged both sides to end attacks immediately. Militants in Hamas-ruled Gaza agreed Sunday to a weeklong cessation of hostilities.

Obama's press secretary, Robert Gibbs, told Fox News Sunday the incoming president's inaugural address will stress responsibility and openness — from the government and financial institutions, for example.

The man elected as the 44th president of the United States will be sworn in at noon ET on Tuesday.

On Sunday, he arrived at Arlington National Cemetery in Virginia and laid a wreath at the Tomb of the Unknowns. The ceremony was one of a number of events scheduled before his inauguration.

Later in the day, Obama and his wife, Michelle, will join vice-president-elect Joe Biden and his wife, Jill, at the Lincoln Memorial in Washington, D.C.

With files from the Associated Press