WASHINGTON—The U.S. is deploying a carrier strike group and a number of bombers to the Middle East to serve as a deterrent to Iran based on new intelligence that suggests allied interests and American forces could be imperiled, multiple U.S. officials said.

The Pentagon is sending a carrier and its accompanying ships as well as what is known as a bomber task force to the region in coming days in response to “a number of troubling and escalatory indications and warnings,” National Security Adviser John Bolton said in a statement Sunday.

“The United States is not seeking war with the Iranian regime, but we are fully prepared to respond to any attack, whether by proxy, the Islamic Revolutionary Guard Corps, or regular Iranian forces,” he said.

The move, which comes after top-level discussions over the weekend, is considered a significant deployment of forces to a region from which the U.S. has been gradually drawing down its military footprint as it realigns its security priorities to compete with Russia and China.

Officials said new intelligence about the threat posed by Iran has alarmed the White House and is the trigger for the deployment, which has only been under discussion in recent days.

The move to deploy additional forces to the region was based on a specific threat to U.S. forces operating in the region, according to a U.S. official. There have been indications recently of Iran or its proxies assembling and moving assets both on land and at sea, the official said.

The deployment comes weeks after the White House decided to designate Iran’s Islamic Revolutionary Guard Corps as a foreign terrorist organization, which Iran has cast as an American provocation.

Top officials gathered in the past couple of days for an emergency meeting to discuss new intelligence assessments on Iran. U.S. officials described the fresh concerns as troubling and that they specifically prompted them to restore some of the American military assets to the region which are no longer kept there on a regular basis as the U.S. has shifted more of its focus to other parts of the world.

The carrier USS Abraham Lincoln and its accompanying ships, which recently deployed from Norfolk, Va., may have ended up in the Persian Gulf eventually, but this move sends it there directly, officials said.

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In the past, B-1 Lancers or B-52 Stratofortresses strategic bombers have been based at al-Udeid air base in Qatar. The U.S. has maintained a carrier in the Persian Gulf for years, but more recently minimized such deployments in favor of putting limited assets such as carriers and jet fighters in other areas of the globe. The deployment is expected to restore, at least for now, some of the military assets that have been removed from the region, officials said.

While President Trump has attempted to lean away from conflicts in the Middle East and has sought for example to bring troops home from where they are deployed fighting Islamic State in Syria, some of his senior advisers, including Mr. Bolton, are seen as more aggressive.

The Trump administration has been pushing to drive Iran’s oil exports to zero and has taken other steps to ratchet up the economic pressure on Iran, including by designating Iran’s Islamic Revolutionary Guard Corps as a foreign terrorist organization.

The administration’s larger goal is to dissuade international companies from doing business with important sectors of the Iranian economy and, thus, induce Tehran to cease its support for militant groups and pull back militarily in the region.

But the administration’s policy has raised concerns that pushing the Iranian regime into a corner might cause it to lash out, either directly with its own forces or through proxies, at Western facilities or perhaps those of the U.S.’s Arab allies in the Persian Gulf region.

In recent years, the U.S. and Iran have been careful not to get into a military confrontation. During the campaign against Islamic State, U.S. forces in Iraq and Iranian-backed militias avoided targeting each other and instead focused on their common foe. The U.S. shot down two Iranian drones in 2017 that approached Syrian fighters the U.S. were training to fight ISIS in southeast Syria, but that episode didn’t escalate.

More recently, there have been concerns that military tensions might grow.

In September, the U.S. said that it was closing its consulate in Basra, Iraq, after rockets or mortars landed several hundred meters from the structure. Iranian officials denied Tehran was responsible and noted that Iran’s own consulate in Basra was burned to the ground during violent demonstrations in the city.

But Secretary of State Mike Pompeo warned at the time that the U.S. would hold Iran responsible for any harm done to Americans or U.S. diplomatic facilities “whether perpetrated by Iranian forces directly or by associated proxy militias.”

Iranian Foreign Minister Javad Zarif also warned last month of a potential military confrontation in the region, though he insisted that it wouldn’t be caused by Iran but could be the result of a miscalculation or a provocation by Iran’s enemies.

Shifting additional forces to the Middle East as a deterrent against Iran would represent something of a course correction for the Pentagon, which has sought to move forces away from the region so it could build up its capability to deter possible aggression by Russia and China.

—Vivian Salama contributed to this article.

Write to Gordon Lubold at Gordon.Lubold@wsj.com and Michael R. Gordon at michael.gordon@wsj.com