The United States will move 500 troops to Lithuania in October for a six-month deployment, returning to the Baltic region where it first sent soldiers after Russia's annexation of Ukraine's Crimea peninsula in 2014.
The U.S. military presence, part of a broader NATO deterrent, is likely to reassure Baltic allies that U.S. President Donald Trump remains committed to Europe's eastern flank despite recent Pentagon cuts to European defence projects.
"The message is that the U.S. forces can arrive whenever and wherever they might be needed, with the forces that might be needed," said Lithuania's Defence Minister Raimondas Karoblis.
"The U.S. is choosing to improve mobility of their troops, as opposed to having a permanent presence," he told Reuters.
The United States has invested in Europe to counter any potential Russian aggression, spending on training, military base modernisation and storing U.S. equipment, but Trump has also called on allies to spend more on defence.
Moscow says it has no intention of invading the Baltics or Poland and accuses NATO of destabilising Europe by moving troops closer to Russia's borders.
Troops from allies including Britain, Canada, France and Germany have been rotating through fellow NATO members Poland and Lithuania, Latvia and Estonia since Russia's annexation of Crimea in March 2014.
The new U.S. troops will bring 30 Abrams tanks, which Lithuania's defence minister said was more than in similar sized deployments, 25 Bradley armoured vehicles and 70 other vehicles.
The troops will leave after a military exercise in spring 2020, rehearsing defence of so-called Suwalki Gap, the only land route between the Baltic States and the rest of the NATO.
Both Lithuania and Poland have a border in the northeast with the Russian enclave of Kaliningrad, where Moscow has deployed advanced nuclear-capable Iskander missiles.
In the search for funds to pay for a wall on the U.S.-Mexico border, the Pentagon this month released a list of projects in Europe that would no longer be funded by Washington's European Deterrence Initiative, or EDI, worth some $700 million.
