WASHINGTON — Two Senate Foreign Relations Committee Democrats hit the Sunday talk shows to deliver a message to the White House: One way or another, Congress is going to weigh in on any potential deal with Iran.

Congressional Democrats and the Obama White House have been sharply critical of a letter freshman Senate Armed Services Committee member Tom Cotton of Arkansas and 46 other upper chamber Republicans sent Iranian leaders last Monday. In it, the GOP signatories warned Congress would not support the reported terms a possible deal currently under negotiation.

But even in the wake of the letter fracas, many Senate Democrats still agree with Republicans that lawmakers should have a role in determining whether sanctions against Iran that Congress approved should be eased or lifted.

"Our objective is to get an agreement with Iran where they give up their nuclear weapon of breakout capacity," Sen. Ben Cardin, D-Md., said on "Fox News Sunday."

"We want this president to have the strength of the United States behind this negotiation. The letters signed by the 47 senators weakened the president's negotiating ability," he said. "That was wrong. There's no agreement yet. We have to give the president the opportunity to negotiate an agreement because that is the best option for the United States."

But Cardin, the third-ranking Democrat on the panel, added: "The Congress is going to have to be engaged here. We imposed the sanctions."

Appearing on NBC's "Meet the Press" program, Sen. Tim Kaine, D-Va., delivered a similar message.

"If they go to the [United Nations] about international sanctions, they have the complete ability to do that," Kaine said. "Sanctions that the White House has entered into without Congress, they have the ability to take action about without Congress."

But, he added of administration officials, "when they touch upon congressional sanctions, Congress is going to be involved."

In a letter sent Saturday to Foreign Relations Committee Chairman Bob Corker, R-Tenn., White House Chief of Staff Denis McDonough said the administration agrees that Congress has a role in approving any deal. He added that the White House knows lawmakers "will have to take a vote" on any deal.

There was bipartisan support for a Foreign Relations Committee bill that would require a congressional vote — enough, members said, for 67 votes. That is the number needed to override a presidential veto.

The chamber still could vote on that measure, a vote on which Majority Leader Mitch McConnell, R-Ky., delayed under pressure and a filibuster threat from Democrats. They want to wait and vote after March 24, a key deadline in global powers' negotiations with Iran.