WASHINGTON — A bipartisan group of lawmakers is pushing the Pentagon to expedite a monthslong review aimed at determining whether the United States should send its MQ-1C Gray Eagle drones to Ukraine.

Seventeen House Democrats and Republicans on Thursday sent a letter to Defense Secretary Lloyd Austin, pressing him to expedite an ongoing risk assessment to determine whether transferring the technology poses a risk should it fall into Russian hands.

“There continue to be delays in delivering Gray Eagle systems to Ukraine despite urgent requests from Ukraine’s Minister of Defense Oleksii Reznikov and ambassador to the U.S. Oksana Markarova,” the lawmakers wrote. “While important, thorough risk assessments and mitigation should not come at the expense of Ukrainian lives.”

Pentagon officials have been mulling a request for Gray Eagle drones from Ukraine since at least April, but it’s hung up over concerns about securing the technology as well as its survivability in the contested airspace above Ukraine. Officials said they are also considering the potential impact on the U.S. military’s readiness if the drone is provided from its own stockpiles.

On Thursday, Pentagon spokesman Brig. Gen. Patrick Ryder told reporters that the U.S. has sent Ukraine other intelligence, surveillance and reconnaissance systems including Puma and ScanEagle drones, as well as Switchblade loitering munitions.

“We continue to maintain a robust dialogue with Ukraine and the international community about what we and the international community can do to support Ukraine,” Ryder said.

The letter presses the Pentagon on the Gray Eagle and the MQ-9A Reaper, which are both made by General Atomics of San Diego, California. The U.S. has sold Reapers to the U.K., France and others, but has not exported the Gray Eagle, which can be armed with up to four Hellfire missiles.

The lawmakers, led by Reps. Marcy Kaptur, D-Ohio, Brian Fitzpatrick, R-Pa., Mike Quigley, D-Ill., and Andy Harris, R-Md., called for completing the review “in a timely manner.”

“Should the decision be made to transfer Gray Eagles, then it should be done expeditiously,” they wrote. “Or, if the determination is to withhold this technology, that needs to be communicated quickly and clearly to afford our Ukrainian partners the opportunity to make alternative plans.”

House Intelligence Committee Chairman Adam Schiff, D-Calif., also signed onto the letter.

Contacted about the letter Thursday, General Atomics spokesman C. Mark Brinkley criticized the U.S. government’s “endless wait-and-see response” amid months of discussions with Washington and Kyiv over the merits of the move.

The company has offered to train Ukrainian operators at no expense to American taxpayers and, Brinkley said, responded to “repeated concerns about technology transfer and provided options for increased battlefield survivability.”

“If you think HIMARS [the High Mobility Artillery Rocket System] changed things, put some Gray Eagles in the air and see what happens next,” Brinkley said. “No one wants to see the significant gains made by the Ukrainians erode due to inaction.”

Joe Gould was the senior Pentagon reporter for Defense News, covering the intersection of national security policy, politics and the defense industry. He had previously served as Congress reporter.

Bryant Harris is the Congress reporter for Defense News. He has covered U.S. foreign policy, national security, international affairs and politics in Washington since 2014. He has also written for Foreign Policy, Al-Monitor, Al Jazeera English and IPS News.

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