WASHINGTON: The United States warned Saturday that it would not allow Iran to “slow walk” international negotiations over its nuclear program, a day after heaping blame on Tehran for the stalled process.

“We can’t accept a situation in which Iran accelerates its nuclear program and slow walks its nuclear diplomacy,” said a senior administration official.

The official said the United States was not yet planning to walk away from the talks in Vienna, but that it hoped Iran would return “with a serious attitude.”