MANCHESTER, United Kingdom - British Prime Minister Rishi Sunak on Wednesday axed a key section of England's new high-speed railway, diverting billions of pounds instead into improving existing transport routes in the north.

Addressing his Conservative party's annual conference in Manchester, Sunak said HS2 would no longer run on high speed rails to the city in northwest England, with the government spending the £36 billion ($44 billion) saved on improving current train and road networks.

HS2, Britain's second high-speed train line, has suffered massive delays and ballooning costs but will still run between London and the nation's second biggest city, Birmingham, from around the end of the decade.

"I am ending this long-running saga," Sunak said Wednesday.

"I am cancelling the rest of the HS2 project and in its place, we will reinvest every single penny, £36 billion, in hundreds of new transport projects in the North and the Midlands, across the country."

The project's costs had almost trebled to more than an estimated £100 billion from £37.5 billion in 2013, even before taking into account the recent surge in inflation, making it one of the world's most expensive lines.

Faced with mounting costs, a big chunk of the project had been derailed already before Wednesday's announcement.

The government in 2021 pulled the plug on the route linking Birmingham to the city of Leeds in northern England.

HS2, aimed at faster journey times and taking capacity off existing busy routes, was at the forefront of the government's grand scheme to "level up" the economy by providing better infrastructure to the north.

London and southeast England have long been seen as benefiting from major transport projects, while the north has lost out.

"I say to those who backed the project in the first place, the facts have changed," Sunak told the party conference.

"And the right thing to do when the facts change is to have the courage to change direction."

High Speed 2 follows Britain's only such fast track, which carries Eurostar trains towards the Channel Tunnel on their way to France.