Reuters- Senior U.S. congressional Republicans said on Thursday they would support new sanctions on Iran, backing up President Donald Trump's aggressive posture toward Tehran including saying it was "on notice" for test-firing a ballistic missile.

Paul Ryan, the Speaker of the House of Representatives, said he would support more sanctions, and that the United States should stop "appeasing" Iran.

"I would be in favor of additional sanctions on Iran," Ryan told reporters at a weekly press conference. I�d like to put as much toothpaste back in the tube as possible. I think the last administration appeased Iran far too much," he said.

Senator Bob Corker, the chairman of the Senate Foreign Relations Committee, told Reuters his committee was "in the early stages" of working on legislation related to the nuclear issue.

He said he had discussed it at the White House with Trump's national security adviser, Michael Flynn, on Wednesday, just before Flynn issued his warning that Washington was putting Iran on notice for its "destabilizing activity."

Corker said the Trump administration would take a stronger stance against Iran, although he did not expect its actions would bring an end to the international nuclear deal.

"The administration, thankfully, is going to follow through on appropriately holding Iran accountable for the violations that are taking place," he told Reuters.

(Reporting by Patricia Zengerle; Additional reporting by Richard Cowan and Susan Heavey; Editing by James Dalgleish)