Prime Minister Boris Johnson says Britain is considering a “major” deployment of troops, warships, and fighter jets in Eastern Europe to counter Russian “hostility” toward Ukraine.

“This package would send a clear message to the Kremlin: We will not tolerate their destabilizing activity, and we will always stand with our NATO allies in the face of Russian hostility,” Johnson said in a statement late on January 29.

The comment comes as NATO members stepped up vows of additional support for Ukraine in the face of a Russian military buildup along their common border in what many in the West fear could be the prelude to an invasion.