Nato is set to approve big increases in the forces deployed on its eastern flank, its secretary-general Jens Stoltenberg has said.
Mr Stoltenberg was speaking at a news conference on the eve of an emergency summit on Russia’s invasion of Ukraine.
He pledged more troops for Hungary, Slovakia, Bulgaria and Romania.
Nato will also agree more support for Ukraine, including greater protection against the use of chemical, biological and nuclear weapons.
US President Joe Biden is on his way to Brussels for the summit on Thursday and for other meetings with European leaders.
“I expect leaders will agree to strengthen Nato’s posture in all domains, with major increases in the eastern part of the alliance. On land, in the air and at sea,” Mr Stoltenberg said.
In all, Nato has about 40,000 troops on its eastern border, stretching from the Baltic to the Black Sea.
“There is a new sense of urgency because we cannot take peace for granted,” Mr Stoltenberg told reporters.
He warned Russia against using nuclear weapons in Ukraine, calling for a halt to Moscow’s “dangerous, irresponsible nuclear rhetoric”.
He added that that any use of biological or chemical weapons would have “far-reaching consequences”, while stressing that Nato was ready to “protect and defend allies against any threat, any time”.
