WASHINGTON – The Pentagon is rushing additional military muscle, including B-52 bombers, to the Middle East to counter Iranian threats to U.S. troops on the ground and at sea, the Pentagon announced Tuesday.

The announcement follows two days of increasing alarm over threats from Iran. National Security Advisor John Bolton said Sunday that the USS Abraham Lincoln aircraft carrier and bombers were being sent to the region. Meanwhile, senators from both parties urged the White House to move cautiously.

By Monday, Pentagon spokesman Charles Summers was pointing "to indications of heightened Iranian readiness to conduct offensive operations against U.S forces and our interests."

On Tuesday, the Pentagon fleshed out the nature of its response. The Air Force is dispatching B-52 bombers, long-range warplanes capable of carrying 70,000 pounds of bombs.

The Abraham Lincoln, which already was scheduled for deployment to the Persian Gulf region, is cutting short other port visits to arrive ahead of schedule. The aircraft carrier, with a wing of warplanes and 3,000 sailors aboard, is accompanied by the USS Leyte Gulf, a guided-missile cruiser, and four destroyers: the USS Bainbridge, Gonzalez, Mason and Nitze.

"U.S. Central Command continues to track a number of credible threat streams emanating from the regime in Iran throughout the CENTCOM area of responsibility," Navy Capt. Bill Urban, a Central Command spokesman, said in a statement.

The escalating tensions follow an announcement last month by Secretary of State Mike Pompeo of new sanctions against any country, including U.S. allies, that imports Iranian oil, the country's top source of income. The White House also designated the Revolutionary Guards Corps as a foreign terrorist organization, part of a hardening stance toward Iran.

Pompeo, who canceled a long-planned visit with Germany's Angela Merkel, made an unannounced stop in Baghdad instead on Tuesday to meet with the country’s intelligence and defense chiefs, among other officials. He said he wanted to discuss the new threats from Iran with Iraqi leaders.



"Iran is escalating their activity," Pompeo told reporters en route to Baghdad. "I wanted to go to Baghdad to speak with the leadership there, to assure them that we stood ready to continue to ensure that Iraq is a sovereign, independent nation."

Sen. Rand Paul, R-Ky, warned against any U.S. military action against Iran.

“I think it’s very important that the administration know they do not have our permission to (engage in) … any kind of war or regime change operation in Iran.”

Asked if he is worried about Bolton pushing for military action, Paul said: “I think that the president’s instincts are good on this and hopefully he’ll listen to his inner voice.”

Sen. Tim Kaine, D-Va., in a statement, said the White House was being reckless in confronting Iran and lacked legal authority to start a conflict.

“I’m deeply worried that the Trump administration is leading us toward an unnecessary war with Iran," Kaine said.

To others, the deployment makes sense as a warning to Iran, said Michael O'Hanlon, a senior fellow at the Brookings Institution.

"I like the decision, to the extent I can understand the backdrop to it, because it tells Iran they won’t get away with doing something nasty by proxy," O'Hanlon said. "We are on to them. That may or may not suffice as deterrent, and we have to be careful about assuming that a carrier or bomber can stop a covert operative, but I still favor it – and I also favor reminding Iran that we aren’t really pivoting out of the Middle East too too dramatically, either."

More:President Trump moves to cut off Iran oil exports; decision could roil markets

There are thousands of U.S. troops in the region, many of them in Iraq, Iran's neighbor to the west. During the bloody insurgent war there, hundreds of U.S. troops were killed by weapons the Pentagon said were furnished by Iran.

Read more:Download the USA TODAY app