U.S. Secretary of State John Kerry on Tuesday expressed optimism that the Obama administration will garner enough support from Congress to implement the Iran nuclear deal.

"We're going be successful on plan A," Kerry said at a discussion in New York when asked what the White House would do if Congress kills the deal. "That's our policy, and I'm quite confident we're going to be."

At the discussion on the nuclear deal reached by six world powers and Iran last month, Kerry continued to defend the accord, warning of consequences if Congress rejects it in a vote in September. President Barack Obama has reiterated that he would veto any plan of disapproval of the deal by Congress.

"That is a recipe, very quickly...for the American dollar to cease to be the reserve currency of the world, which is already bubbling out there," Kerry said.

Senator John McCain, chairman of the Senate Armed Services Committee, said Tuesday that there will be enough votes to pass the resolution of disapproval against the deal, but he is less sure on getting enough support to override the president's veto, news website The Hill reported.