"We will agree to deploy by rotation four robust multi-national battalions in the Baltic states and Poland," Stoltenberg told a news conference ahead of a meeting of NATO defence ministers in Brussels tomorrow.
"This will send a clear signal that NATO stands ready to defend any ally," he said, referring to a whole series of measures the US-led alliance has taken since the Ukraine crisis to counter a more assertive Russia.
Stoltenberg did not say how many troops would be deployed in the four battalions but officials previously have said they will number 2,500-3,000, acting as a tripwire to deter Russia and reassure nervous alliance members once ruled from Moscow.
The NATO chief stressed that the deployment-to be made on a rotational basis, not permanent so as not to infringe existing treaties with Russia-was part of a much wider response to the Ukraine crisis.
It also includes pre-positioning equipment and headquarters units so these troops can hit the ground running in any fresh crisis.
Topping off the revamp is a commitment by NATO's 28 member states to reverse years of spending cuts and devote two percent of total national economic output to defence within a decade.
Stoltenberg said progress was being made in this crucial area, with the allies spending 0.6 per cent more on defence last year and an increase of 1.5 per cent expected in 2016.