SALT LAKE CITY — Utah Sen. Mike Lee and Vermont Sen. Bernie Sanders are working together to blunt a Trump administration move to allow the sale of some types of military weapons to other countries.

Lee, Sanders, Sen. Chris Murphy, D-Conn., Sen Chris Coons, D-Del., and Sen. Rand Paul, R-Ky., have introduced legislation that would amend the Arms Export Control Act to prohibit the export of certain weaponized unmanned aircraft systems.

Lee fears the drones might end up in the ongoing Saudi-led civil war in Yemen. He and the other senators have repeatedly called for an end to U.S. involvement in the conflict.

“I am concerned that making it easier for the United States to export weapon-capable UAS systems to Saudi Arabia and the United Arab Emirates further entrenches the U.S. role in the war in Yemen and perpetuates an incentive structure for keeping rather than drawing down U.S. presence in the Middle East,” he said in a statement.

Democratic presidential candidate Bernie Sanders speaks to his supporters during a rally at the Utah State Fairpark in Salt Lake City on Monday, March 2, 2020. Thousands turned out to see the party front-runner a day before Super Tuesday voting in Utah and 13 other states. | Steve Griffin, Deseret News

The bill would prohibit the export, transfer or trade of covered unmanned aircraft systems while allowing exceptions for NATO members, Australia, Israel, Japan, New Zealand and South Korea.

There have been restrictions since 1987 on the proliferation of ballistic and cruise missiles, rockets and unmanned aircraft by the Missile Technology Control Regime, an informal agreement among 35 countries to slow the ability of adversaries to acquire equipment for weapons of mass destruction.

The agreement — of which the U.S. is a participant and founding member — has made it more difficult for “nefarious” actors like Iran and North Korea to get weapons delivery systems, according to the senators.

The Trump administration says the agreement regarding standards for unmanned aircraft systems needs be modernized.

Not only do the outdated standards give an unfair advantage to countries outside the agreement and hurt American industry, they also hinder U.S. deterrence abroad by handicapping allies with subpar technology, the White House says.

Last month, President Donald Trump downgraded the classification of some of those systems, which allows them to be sold abroad.

While there are some NATO and Indo-Pacific allies who are interested in buying those systems, Saudi Arabia and the UAE have expressed repeated interest in them, which would only better enable them to continue the war in Yemen, according to the senators.

Murphy said selling weaponized drones into the Middle East could bring disastrous consequences.

The agreement has worked well for decades, “and the president is willing to blow it up in order to continue the blank check approach he has taken with Saudi Arabia and the UAE,” he said. “If we allow Trump to start selling drones, we set a dangerous precedent that allows and encourages other countries to sell missile technology and advanced drones to our adversaries.”

The president’s action would also further enable the Saudis to continue killing more innocent civilians in Yemen by supplying them with advanced U.S.-made drones, Murphy said.

Congress, he said, can “stop Trump in his tracks” by making some of the limits in the agreement legally binding.

“Doing so will protect innocent civilians, stop an arms race from spiraling out of control, and strengthen U.S. national security and our interests abroad,” Murphy said.

The U.S. has supported Saudi Arabia in the war against the Houthis, an Islamic sect that seized the Yemeni the capital of Sanaa and other parts of the country more than five years ago.

Tens of thousands of civilians have been killed or wounded. The fighting has created refugees, orphans and widows and displaced countless families. Millions of people lack access to food and clean water and face rampant disease.

The Trump administration contends the U.S. military is not engaged in hostilities between the Saudi-led coalition and the Houthi forces. The U.S. has provided limited support, including intelligence sharing, logistics and, until recently, aerial refueling, according to the White House.

Lee said the U.S. is helping Saudi Arabia bomb its enemies.

“If that doesn’t constitute hostilities, I don’t know what does,” he said in a 2018 Senate floor speech.