WASHINGTON (AP) – The Obama administration will leave open the door for discussions with Iran over its nuclear ambitions even as demonstrators question the legitimacy of President Mahmoud Ahmadinejad’s re-election, administration officials said Sunday.

Ahmadinejad has accused the West of stoking unrest, singling out Britain and the United States for alleged meddling. Last week, Iran expelled two British diplomats, and Britain responded in kind. Iran, which detained nine British Embassy employees Saturday before releasing four, has said it’s considering downgrading diplomatic ties with Britain.

The U.S. has not had diplomatic relations with Tehran since the aftermath of the Iranian revolution in 1979. On Saturday, Ahmadinejad said he would make the U.S. regret its criticism of the postelection crackdown and said the “mask has been removed” from Obama’s efforts to improve relations.

Susan Rice, the U.S. ambassador to the United Nations, said Sunday that Ahmadinejad is falling back on his government’s usual strategy of blaming the West and the U.S. in particular for its internal problems.

“This is a profound moment of change. And what Ahmadinejad says to try to change the subject is, frankly, not going to work in the current context, because the people understand that the United States has not been meddling in their internal affairs,” she said.

The legitimacy of the government, while questioned by the people of Iran, is not the critical issue for the U.S. goal of preventing Iran from developing a nuclear capability, Rice said.