By David Lawder

NUSA DUA, Indonesia (Reuters) -U.S. Treasury Secretary Janet Yellen said the United States will impose new sanctions on a transnational network of individuals and companies that have been working to procure military technologies for Russia's war effort in Ukraine.

Yellen told reporters on the sidelines of the G20 summit in Bali the sanctions would target 14 individuals and 28 entities, including financial facilitators, but she declined to provide details on where they were located. She said the announcement was scheduled for later on Monday.

"This is part of our larger effort to disrupt Russia's war effort and deny equipment it needs through sanctions and export controls," Yellen told reporters.

She declined to provide details on which technologies the sanctions would target in an effort to cut off Russian purchases.

The U.S. Treasury has sanctioned major military industrial firms in Russia and the Commerce Department has cut off exports of American-made components and U.S. technologies that have been used in some of Russia's military hardware. Yellen said these were already having an impact on the battlefield in Ukraine.

Russia has managed to procure drones from Iran that have been used to attack cities and power infrastructure in Ukraine. Iranian military entities and industries are already under heavy U.S. sanctions over Tehran's nuclear development program, and it was unclear whether any of the sanctions were related to those drone munitions purchases.

Yellen also said that at the same time the United States would continue to support Ukraine with financial and economic aid. The Biden administration has requested an additional $4.5 billion in non-military assistance from Ukraine, and Yellen said that, once congressional approval was secured, the Treasury would immediately begin disbursing it to Ukraine.