President Barack Obama says a letter from Republican senators to Iranian leaders is ironic because, in his words, some members of Congress appear to want to align themselves with �hardliners� in Iran.

Obama says, �It�s an unusual coalition.�

In the letter, Republicans said that without congressional approval, any deal between Iran and the U.S. would be merely an agreement between Obama and Iran�s supreme leader, Ayatollah Ali Khamenei.

Obama says he will concentrate on seeing whether negotiators with Iran can strike a deal.

Earlier, White House Press Secretary Josh Earnest said the GOP letter interferes with diplomatic negotiations. He called it a �rush to war, or at least the rush to the military option� that was not in the best interest of the United States.�

(AP)