AstraZeneca said: “The site will continue to produce and supply our flu vaccine, for patients in the UK and around the world.”
It added that none of the current jobs at the Speke site would be affected.
The Labour government has made boosting growth its key objective and has been trying to encourage more firms to invest in the UK.
On Wednesday, Reeves named AstraZeneca as one of the “great companies” as she set out her plans to grow the economy, saying she was “determined to make Britain the best place in the world to invest”.
Plans to expand AstraZeneca’s site at Speke had been set out by the previous Conservative government in last March’s Budget by Reeves’ predecessor, Jeremy Hunt.
There have been subsequent reports that talks between the company and the Labour government had run into delays.
AstraZeneca also said the amount of support offered did not match the level put forward by the previous government.
