WASHINGTON, DC, United States (AP) — In a new show of military might, two American bomber aircraft flew from the United States to the Middle East yesterday in a round-trip mission that US officials said covered a wide swath of the region and was a direct message of de terrence to Iran.

The flight of the two massive B-52H Stratofortress bombers, the second such mission in less than a month, was designed to underscore America’s continuing commitment to the Middle East, even as President Donald Trump’s Administration withdraws thousands of troops from Iraq and Afghanistan.

The long-range heavy bombers, which are capable of carrying both conventional and nuclear weapons, are a formidable sight and are flown less frequently in the Middle East than smaller combat aircraft, such as American fighter jets. Adversaries often complain about bomber flights in their region, deeming them a provocative show of force.

“The ability to fly strategic bombers halfway across the world in a non-stop mission and to rapidly integrate them with multiple regional partners demonstrates our close working relationships and our shared commitment to regional security and stability,” General Frank McKenzie, the top US commander for the Middle East, said in a statement.

The troop cuts, coupled with the impending departure of the USS Nimitz aircraft carrier strike group in the Gulf, have fueled allies’ concerns that the US is abandoning the region. Those worries are compounded by fears that Iran may strike out at the US or allies in retaliation for the assassination of Iranian nuclear scientist Mohsen Fakhrizadeh.

Iran has blamed the death on Israel, which has been suspected in previous killings of Iranian nuclear scientists.

US officials are also worried about a possible Iranian retaliatory strike on the anniversary of the US airstrike that killed Iran’s top general, Qassem Soleimani, and senior Iraqi militia leaders near Baghdad’s airport in early January.

Iranian-backed militias routinely launch rockets near installations in Iraq where US and Iraqi troops are based, and officials worry about a larger, more deadly assault.

“We do not seek conflict,” McKenzie said, “but we must remain postured and committed to respond to any contingency or in opposition to any aggression.”

A senior military official, who spoke to a small group of reporters on the condition of anonymity to provide details of the mission, said the Administration believes that the risk of an Iranian attack on US or allied interests in the region is a bit higher than normal now, and the Pentagon wants to ensure that Tehran thinks twice before doing anything. Adding to the concerns is the presidential transition in the US following Joe Biden’s November victory over Trump. The official said Iran or other adversaries often believe the US may be weaker or slower to respond during a political transition, which American officials flatly deny.