The United States has dismissed reports that Russia is in fact withdrawing troops from Ukraine’s border, instead accusing Moscow of sending more soldiers as fears of an invasion grow.

Multiple reports are now coming in that appear to contradict Putin’s earlier claims of a “partial” drawdown of Russian forces, including from Crimea, after the completion of military drills in the region.

A senior US administration official spoke to the Associated Press on condition of anonymity, saying the west detected that Russia had increased its force near Ukraine by 7,000 troops, with some arriving as recently as Wednesday, and that there had been a marked increase in false claims by Russians that the Kremlin might use as pretext for an invasion.

We continue to receive indications they could launch a false pretext at any moment to justify an invasion.”

The official said those claims included reports of unmarked graves of civilians allegedly killed by Ukrainian forces, statements that the US and Ukraine are developing biological or chemical weapons, and claims that the west is funnelling in guerrillas to kill Ukrainians, the Associated Press reports.

The official said they were not authorised to speak publicly about sensitive operations and could not provide underlying evidence for the assertions.

Britain’s defence intelligence chief made a series of rare public comments late on Wednesday, adding to the west’s scepticism that Russia is committed to de-escalating any conflict.

In case you missed it, Lt Gen Sir Jim Hockenhull said more Russian armoured vehicles, helicopters and a field hospital were spotted despite the Kremlin’s assertion it has withdrawn troops.

We have not seen evidence that Russia has withdrawn forces from Ukraine’s borders. Contrary to their claims, Russia continues to build up military capabilities near Ukraine.

This includes sightings of additional armoured vehicles, helicopters and a field hospital moving towards Ukraine’s borders. Russia has the military mass in place to conduct an invasion of Ukraine.”

US officials have described as “false” Russian claims that it is withdrawing troops. And Nato’s secretary general said on Wednesday that Russia was still building up its forces.