Keita's deal with Liverpool expired in the summer and the Guinea international was not expected to renew his contract at Anfield.

"I'm really looking forward to my new role at Bremen," Keita said in a statement.

"Werder is a special club and I know the Weserstadion from my time in Leipzig. The club and the philosophy suit me, it's the right move for me."

Keita signed for Liverpool from RB Leipzig in 2018 and went on to win the Champions League, Premier League, FA Cup and League Cup during his five-year stay on Merseyside.

"Last year he was still on the pitch in the Champions League final and brings a lot of international experience to the team, which we will benefit from as a team," said Bremen coach Ole Werner (35).

"I'm really looking forward to working with him."

Bremen finished 13th in the Bundesliga this season, two spots clear of the relegation places, in their first campaign since being promoted back to the top flight.

Keita impressed in two years at Leipzig, scoring 17 goals and assisting 15 more in 71 appearances, earning him a 65 million euro (£55m) move to Liverpool.