Washington announced Wednesday that it will fully participate in nuclear talks by major powers with Iran over its nuclear program.

The move, part of US President Barack Obama's plan to deal directly with Tehran on key issues, marked a reversal of the policy that had been adopted by the former US administration led by George W. Bush.

"Obviously, we believe that pursuing very careful engagement on a range of issues that affect our interests and the interests of the world with Iran makes sense," US Secretary of State Hillary Rodham Clinton told reporters.

At a news briefing, US State Department spokesman Robert Wood confirmed that Washington's latest decision on joining the P5+1 (five permanent members at the UN Security Council and Germany) negotiations on Iran's nuclear program was one step in keeping with the Obama administration's willingness to engage directly with Iran on the basis of mutual respect and mutual interests.

"The United States remains committed to the P5+1 process; What is different is that the United States will join P5+1 discussions with Iran from now on," he said, noting the P5+1 group has asked EU foreign policy chief Javier Solana to extend an invitation to Iran "to meet with representatives of the P5+1."

"If Iran accepts, we hope this will be the occasion to seriously engage Iran on how to break the logjam of recent years and work in a cooperative manner to resolve the outstanding international concerns about its nuclear program," he said.

Olive branches from both sides

Wednesday's announcement came amidst a variety of signals from both sides that a major diplomatic shift was in the wind.

Obama, during his presidential campaign, called for talks with Iran without pre-conditions, and Wednesday's announcement apparently marked his latest efforts he has taken to reach out to Iran.

Last month, Obama delivered a televised message to the Iranian people, in which he offered new diplomatic engagement, differing sharply from the belligerent rhetoric of his predecessor.