U.S. moves warplanes and more troops to Eastern Europe.

The Pentagon is moving up to eight F-35 fighter jets and a slew of other warplanes to Eastern Europe, the Baltics and Poland to shore up support for NATO allies following what President Biden called the beginning of Russia’s invasion of Ukraine.

At the direction of the president, Defense Secretary Lloyd J. Austin III also ordered an infantry battalion task force — some 800 troops — to the Baltics, according to a senior Defense Department official. All of the troops and warplanes were already in the European theater, the official said.

The latest orders come as the Biden administration and its European allies called the Kremlin’s recognition of two separatist regions of Ukraine a defiance of international law. Mr. Biden on Tuesday joined European leaders in imposing economic sanctions against Russia for what he termed as a violation of Ukraine’s national sovereignty.

The Pentagon said the additional forces are being repositioned to “reassure our NATO allies, deter any potential aggression against NATO member states, and train with host-nation forces.” The Biden administration has said that it does not intend to send troops into Ukraine, which is not a member of the alliance.

The deployments include the movement of up to eight F-35 fighters from Germany to several operating locations along NATO’s so-called “eastern flank” in Eastern Europe, a battalion of 20 attack helicopters from Germany to the Baltics, and an attack aviation task force of 12 helicopters from Greece to Poland.

Mr. Biden has already deployed 3,000 additional American troops to Poland and Romania.