NATO allies have agreed a plan to have more forces on alert in a fresh move to deter any Russian attack. The plan known as 30-30-30-30, would require NATO to have 30 land battalions, 30 air fighter squadrons and 30 ships ready to deploy within 30 days of being put on alert.
US Secretary of Defence Jim Mattis has been behind the plan that was prompted by concerns that NATO could take months to mobilise in response to an attack.
A large Russian exercise last year, involving what some observers said were 100,000 troops, also raised fears of an incursion into Russian-speaking regions in the Baltic states.
The Kremlin has rejected any such claims and says NATO is the security threat in eastern Europe.
It's believed the US Defence Secretary wants the plan implemented within 18 months. The UK, France and Germany are certain to be key participants.