WASHINGTON (Reuters) - Members of the U.S. Congress complained on Tuesday that President Donald Trump’s administration has not shared enough information with them as tensions flared with Iran, with even some Republicans saying they have been left in the dark.

FILE PHOTO: Chairman of the Senate Judiciary Committee Lindsey Graham (R-SC) speaks to the media after Special Counsel Robert Mueller found no evidence of collusion between U.S. President Donald Trump’s campaign and Russia in the 2016 election on Capitol Hill in Washington, U.S., March 25, 2019. REUTERS/Joshua Roberts/File Photo

Relations between Washington and Tehran have become more fraught following Trump’s decision this month to try to cut Iran’s oil exports to zero and beef up the U.S. military presence in the Gulf in response to what he said were Iranian threats.

Lawmakers, including some of Trump’s fellow Republicans, said they would like classified briefings on those threats and the administration’s decisions. During previous administrations, Congress has been regularly briefed about major national security matters.

Some Democrats said public hearings with senior administration officials also would be appropriate.

Separately on Tuesday, Trump denied a New York Times report that U.S. officials were discussing a military plan to send up to 120,000 troops to the Middle East to counter any attack or nuclear weapons acceleration by Iran.

“I think all of us are in the dark over here,” Republican Senator Lindsey Graham told reporters outside the Senate. Asked if he thought lawmakers would be briefed on the situation, he said, “I hope so.”

Nancy Pelosi, the Democratic Speaker of the House of Representatives, has requested a briefing for House members, but an aide said the administration had not yet agreed.

Senate aides said no briefing had yet been scheduled for the full Republican-controlled Senate, despite appeals from Democrats.

“If Iran is responsible for targeted attacks on our service members stationed around the region or any of our national security assets, we should of course respond appropriately and in a way that deters and prevents further assaults,” said Senator Bob Menendez, the top Democrat on the Senate Foreign Relations Committee.

“But it is hard to justify the administration’s actions thus far since they insist on stonewalling Congress from receiving any specifics about what these increased threats actually are and our strategy to confront them.”

The White House did not immediately respond to a request for comment.

A few congressional committees - including the Senate and House intelligence and the Senate Armed Services panel - said they had arranged briefings for staff or members later this week or had already had one, committee aides said.