KYIV, Oct 12 - As U.S. congressional gridlock delays funding for the war in Ukraine, the Pentagon has been able to improvise and build a new missile launcher from radars and other parts contributed by allies and partners, a senior U.S. defense official said Thursday.

The system will be able to launch AIM-9M Sidewinder missiles, which the U.S. announced Wednesday it will send to Ukraine in the latest aid package, The Associated Press reported.

At the same time, U.S. engineers have been able to work with Ukraine to modify a Soviet-era Buk air defense launcher so that it can fire RIM-7 missiles, which the U.S. has in large quantities. Ukraine has a number of the Buk systems, but its supply of missiles had been dwindling.

Both of those systems, the official said, are moving to Ukraine this fall, in an effort to meet critical air defense needs as it struggles to retake territory the Russians have seized and gain a solid battlefield footing as the muddy season hits ahead of the winter freeze.

The official spoke to reporters on condition of anonymity to provide a battle update.

The innovations have given the U.S. another way to pour weapons into Ukraine, even though Congress has not approved any new funding for the war. A small but vocal contingent of Republican lawmakers opposes sending U.S. money overseas for the fight against Russia and forced its removal from a temporary spending measure that prevented a U.S. government shutdown on Oct. 1.

The Pentagon still has about $5.4 billion available that it can use to pull existing weapons from its stockpile to send to Ukraine. That money is expected to last several months. The U.S., however, only has about $1.6 billion to replenish U.S. stocks that are needed by the military services, and there are greater worries about that running out.

U.S. Defense Secretary Lloyd Austin was in Brussels on Thursday for a meeting of NATO defense ministers. He also led a session of the Ukraine Defense Contact Group on Wednesday with more than 50 defense and military leaders from around the world, to discuss how to meet Kyiv’s current and future war needs.

He announced the latest $200 million aid package on Wednesday, which included an unspecified number of the Sidewinder missiles. And Air Force Gen. CQ Brown, chairman of the U.S. Joint Chiefs of Staff, told reporters the additional commitments of weapons and conversations with allies convinced him “we’re putting Ukraine in a good spot” going into the winter fight. (ap/ez)