Swedish striker Zlatan Ibrahimovic has returned to Manchester United on a year-year contract "to finish what I started," the 35-year-old announced in a club statement on Thursday.

"It was always mine and the club's intention for me to stay. I cannot wait to get back out on that Old Trafford pitch" he said. "I am back to finish what I started."

Ibrahimovic has not played since May after suffering a knee ligament injury in the 2-1 Europa League win over Anderlecht.

He underwent surgery which was expected to keep him out for the rest of the year and, in Thursday's statement, Ibrahimovic suggested he is not ready to make an immediate return.

"I know that I have to take my time to make sure that I am ready," he said.

Although United released the much travelled striker after his one-year contract expired in June, he was allowed to use their training ground to recuperate and has recently posted on Instagram to prove his fitness.

"I have been working hard and will continue to do so to make sure I am in the best possible condition for my return to the pitch," he said.

Ibrahimovic, who will wear the number 10 shirt, scored 28 goals in 46 appearances for the club last season, helping them to win the EFL Cup and Europa Cup.

Manager Jose Mourinho indicated that he is looking to the Swede to play an important part in the second part of the season.

"We are delighted Zlatan is on the road to recovery and we are equally delighted to have his ambition and experience back with us," said Mourinho.

"After his contribution last season he deserves our trust and we will be patient waiting for him to return. I have no doubt that he will be important in the second part of the season."

United are joint top of the league after winning both their opening matches, scoring eight goals without reply against West ham United and Swansea City.

Three of the goals have been scored by Romelu Lukaku, a 75 million pound ($96.08 million) replacement for Ibrahimovic from Everton.

Mourinho is well stocked with striking options, including England international Marcus Rashford and Frenchman Anthony Martial.