WASHINGTON (Reuters) - Russia's defense minister reshuffle was a further indication of Russian President Vladimir Putin's "desperation to sustain" his invasion of Ukraine, U.S. State Department deputy spokesperson Vedant Patel said on Monday.

Putin tapped a civilian economist as his surprise new defense minister on Sunday in an attempt to gird Russia for economic war by trying to better utilize the defense budget and harness greater innovation to win in Ukraine.

(Reporting by Daphne Psaledakis and Humeyra Pamuk; editing by Jonathan Oatis)