A bipartisan group of lawmakers is urging Secretary of Defense Chuck Hagel to cut off U.S. taxpayer dollars to a Russian state-arms dealer, from which The Pentagon is buying helicopters.

Reps. Rosa DeLauro, D-Conn., and Kay Granger, R-Texas, are spearheading the effort, in an attempt to highlight the issue at a moment of high tension between the United States and Russia over the crisis in Ukraine.

The Pentagon has no plans for new purchases of helicopters from Rosoboronexport, the Russian state-arms dealer, but continues to exercise an existing contract to obtain them, mainly for use in Afghanistan.

“Given Russia's recent actions that violate the sovereignty and territorial integrity of Ukraine, including its support of the illegal referendum for Crimean separation, we strongly urge you to terminate these contracts,” wrote the lawmakers.

DeLauro, Granger and Reps. Jim Moran, D-Va., Keith Ellison, D-Minn., and Elizabeth Esty, D-Conn., signed the letter.

Earlier this week, President Obama signed an executive order that allows individuals operating in the Russians arms sector to be subject to sanctions.

“We … strongly urge you to cancel contracts with Rosoboronexport for the delivery of Mi-17s to the Afghan National Security Forces, for supplying spare parts or for the sustained maintenance of these helicopters,” the signatories wrote.

Letter to Defense Secretary Chuck Hagel