New Jersey Gov. Chris Christie said Wednesday that a nuclear Iran would pose the biggest foreign policy threat to the United States, adding that he supports actions by Congress to get involved in the White House’s deal-making with the longtime U.S. foe.

“That’s the biggest one: A nuclear Iran is bad for the world and bad for the United States,” said the Republican, who is in New Hampshire ahead of his likely presidential campaign.

Christie was visiting Chez Vachon, a diner in Manchester, shaking hands with voters eating breakfast when one person asked the governor what he considered the biggest national security threat to America. Christie criticized the proposed agreement reached last month to limit Iran’s nuclear program, and warned that a nuclear Iran could inspire other countries in the Middle East to push for nuclear weapons of their own.

In the face of pushback from the White House, Congress has been lobbying for months to have a greater say in the deal with Iran. The two entities reached a compromise earlier this week, and the White House indicated Tuesday it would support legislation that would let Congress have some input into the deal.

“I’m glad Congress is going to get involved in reviewing any deal the president makes. We need to have some more sober heads other than the president’s looking at this,” Christie said. “And I don’t think it’s a good deal for America the way it’s framed right now.” Read more on CNN.