Satellite images show that Russia recently built a new military base in Crimea, according to a report.

US-allied governments accuse Russian President Vladimir Putin of secretly amassing troops — for unknown reasons — amid fear of an invasion, the Daily Mail reported.

The images show lines of military vehicles and troop tents in Crimea, a Russian-speaking peninsula south of mainland Ukraine that Putin annexed after a disputed 2014 referendum.

An April 13 image, taken by PlanetLabs and published by the Daily Mail, shows “at least 1,000 vehicles” and a substantial number of tents for infantry troops, the newspaper reported.

“It is the highest Russian military deployment at Ukrainian borders ever,” European Union foreign policy chief Josep Borrell reportedly said Monday.

The new images come after President Biden last week offered to Putin a summer summit in Europe without preconditions. Biden appeared to blink this month on a decision to send warships to the Black Sea over Russian aggression in Ukraine. The Pentagon ordered a U-turn by two US destroyers.

Since the Soviet Union broke up in 1991, Russia has supported pro-Russian insurgents in neighboring republics — including shoring up allied breakaway states in Georgia and Moldova.

Putin presided over the annexation of Crimea nearly a decade ago without Ukraine’s consent in a rare present-day boundary change by force.

Russian troop deployments often are murky, but Putin’s government is believed to have deployed troops to Crimea to facilitate the 2014 annexation and to have secretly supported a pair of breakaway provinces in eastern Ukraine’s Donbas region.

In Ukraine, a large number of people speak Russian rather than Ukrainian and the country’s politics alternated between pro-Western and pro-Russian until protests in 2014 that chased out pro-Russian leader Viktor Yanukovych. His ouster sparked pro-Russian protests across Ukraine’s south and east.