The British government signalled its support on Monday for a multi-billion-pound railway line running from north to south across the British capital.

The new Crossrail 2 line would run through tunnels under the city, as well as use upgraded current rail lines and would increase capacity on London's rail system by 10 percent.

The funding was promised by Transport Secretary Chris Grayling.

Crossrail 2 claims the project will support 60,000 new jobs across Britain while under construction and 200,000 jobs across London and the southeast region once operational.

The project is expected to cost 30 billion pounds (about 39 billion U.S. dollars).

Secretary Grayling said: "I am a supporter of Crossrail 2, but given its price tag we have to ensure that we get this right."

Cost will be shared by the British government and London, with London expected to pay half the cost.

London Mayor Sadiq Khan said: "Crossrail 2 is essential for the future prosperity of London and the Southeast, so I'm pleased that the transport secretary and I have reached an agreement to take this vital project forward."

Grayling said he and Khan would develop plans "so that the public gets an affordable scheme that is fair to the UK taxpayer."

The two said in a joint statement: "There is no doubt London needs new infrastructure to support its growth." (1 British pound = 1.30 U.S. dollars)