LONDON (Reuters) -Britain will invest over six billion pounds ($8.13 billion) in its submarine building capacity, supporting firms like defence group BAE Systems and engineering multinational Rolls-Royce, finance minister Rachel Reeves is set to announce on Tuesday.

Responding to U.S. President Donald Trump's insistence that Europe take more responsibility for its own security, Prime Minister Keir Starmer has pledged the largest sustained increase in British defence spending since the end of the Cold War.

Last week, Britain said it would increase the size of its nuclear-powered attack submarine fleet to as many as 12, up from the current seven, responding to an independent review of its current military capacity and ability to meet future threats.

No cost was given at the time but in a speech on Tuesday Reeves will say that investments in the defence nuclear sector will include over six billion pounds to boost the "capacity, capability and productivity of the UK's submarine industrial base", including at BAE Systems and Rolls-Royce Submarines, a subsidiary of Rolls-Royce.

The investment, which will cover the four-year spending review period, will help companies deliver the increase in submarine production rate announced last week, the government said in a statement.

Reeves will announce the results of her first multi-year spending review on Wednesday, including an investment of four billion pounds over the next decade in its Plymouth naval base.

The finance minister will also announce an investment in the redevelopment of a naval base in Scotland and in Sheffield Forgemasters, a steel company that produces components for submarines.

($1 = 0.7387 pounds)

(Reporting by Catarina Demony; Editing by William James)