The U.S. Department of Defense has ordered additional few thousand U.S. troops to be put on standby in case they are deployed to Europe due to the tense situation around Ukraine, the Wall Street Journal (WSJ) said, citing U.S. officials.

"The Pentagon has also ordered several thousand more troops be put on standby for deployment [to Europe], in addition to the 8,500 forces who received such an order last week," the publication said.

The Pentagon is expected to announce later Wednesday that U.S. President Joe Biden has given formal approval to deploy additional forces in Eastern Europe.