Britain's Defence Secretary, Michael Fallon, is expected to release details of the commtment Thursday at a meeting of NATO defense ministers.
"The length of the troop deployment will be open-ended but on a rotational basis — a formulation that will allow the US, Britain and Germany to avoid accusations that they are breaching agreements struck with Moscow after the end of the cold war," the FT said.
However, the numbers of troops involved wold be relatively small with company-sized force of around 100 troops most likely.
"Mr Fallon is to tell fellow defence ministers that Britain is “committed to supporting the sovereignty of the democratic nations of eastern Europe”, the FT said, citing a UK Ministry of Defence source.
Britain's forces will be part of a deal agreed in June called the Transatlantic Capability Enhancement and Training initiative which aims to combine force cooperation for soldiers from the US, Germany and other NATO members in a single plan.
Latvian Defense Minister Raimonds Bergmanis said Thursday he expected to be briefed about the plan by Fallon later in the day.