Britain on Friday formally began building HS2, its new high-speed railway set to deliver thousands of jobs to the country's virus-ravaged economy.

Prime Minister Boris Johnson said the project -- which is to cost more than £100 billion ($130 billion, 110 billion euros) funded mostly by the state -- will play a part in helping the country get back on its feet following the pandemic.

Prior to the virus outbreak, Johnson saw HS2 as a key infrastructure project aimed at helping drive Britain's post-Brexit economy.

"HS2 is at the heart of our plans to build back better (following the pandemic) and with construction now formally underway, it's set to create around 22,000 new jobs," Johnson said in a statement Friday.

The start of construction comes amid huge financial losses for Britain's rail sector as office workers shun public transport to work from home during the virus outbreak.

Despite this, Johnson later told an event to mark the start of building works that he has "absolutely no doubt that mass transit transport infrastructure is going to be crucial for our country, not just now, but in the decades ahead".

HS2, while quickening train journeys between London in southeast England and major cities in the north, will also ease pressure on existing lines and possibly help rebalance a UK economy that is heavily centred on the capital. 

"As the spine of our country's transport network, the project will be vital in boosting connectivity between our towns and cities," Johnson said Friday.

"But HS2's transformational potential goes even further. 

"By creating hundreds of apprenticeships and thousands of skilled jobs, HS2 will fire up economic growth and help to rebalance opportunity across this country for years to come," he added.

The project's first stage -- connecting London to Britain's second-biggest city Birmingham in the English Midlands -- is due to open by around 2028-2031. 

A second phase, extending the line north to English cities Manchester and Leeds, won't be completed before 2035-2040.

And while construction of HS2 is set to produce vast amounts of carbon emissions and destroy ancient woodlands and wildlife, according to experts, its electric trains will likely be far more environmentally friendly than planes making similar trips.

HS2 is Britain's second high-speed rail project after HS1, which links London with the Channel Tunnel that connects the UK to France.