Donald Trump has named former "never Trumper" Republican and Ohio Senator JD Vance as his vice-presidential nominee.

Republican National Convention (RNC) delegates formally selected Mr Vance, 39, on Monday after Trump announced on his social media platform he had chosen him after "lengthy deliberation and thought".

Mr Vance is a Yale-educated venture capitalist and author of the bestselling memoir-turned-film Hillbilly Elegy.

He has previously criticised his new running mate, once suggesting privately that Trump could be "America's Hitler", but has since become an ardent supporter of the former president.

In the 2022 midterm elections, he won a seat in the US Senate with Trump's endorsement.

A native of Ohio, Mr Vance gained attention after the release of Hillbilly Elegy, which tells of his blue-collar upbringing and how it affected his politics.

Trump said on the Truth Social platform that the book "championed the hardworking men and women of our country".

"As Vice President, J.D. will continue to fight for our Constitution, stand with our Troops, and will do everything he can to help me MAKE AMERICA GREAT AGAIN," he continued.

Mr Vance was confirmed to the Republican ticket at the RNC, which is taking place this week in Milwaukee, Wisconsin.

He entered the venue on Monday accompanied by his wife, Usha, and greeted delegates as a country song played with the chorus "let's build America first".

Addressing the crowd in the basketball arena where the event is taking place, Bernie Moreno, an Ohio Senate candidate, said: “To JD, America first isn’t just a slogan. It’s his north star.”

"It's an incredible pick," said Donald Trump Jr, Trump's son, at the RNC. "Truly a great choice."

The choice came before the opening of the RNC in Milwaukee on Monday, and two days after Trump survived an attempt on his life at a rally in Pennsylvania.

In the aftermath, Mr Vance tweeted that Democratic Party rhetoric had "led directly to President Trump’s attempted assassination”.

Trump has said he will tone down his RNC speech and call for national unity.

JD Vance, MAGA man

Mr Vance has become an increasingly important player in the world of Make America Great Again [MAGA] politics.

The choice suggests the former president knows that this election will be won and lost in a handful of industrial Midwest battleground states - Pennsylvania, Michigan and Wisconsin.

In the Senate he has been one of the biggest congressional sceptics of aid to Ukraine.

In recent months, he has introduced bills to withhold federal funds for universities where students have protested over the Gaza war or that employ undocumented immigrants.

He sponsored legislation in March that would cut the Chinese government out of US capital markets if it does not follow international trade law.

He has also frequently appeared at Trump's campaign events, and travelled to New York City to attend Trump's fraud trial.

Mr Vance, who was baptised as a Catholic in 2019, is anti-abortion. He has backed Trump's repeated statement that the issue is a matter for individual states.

Mr Vance is a former US Marine who was deployed to Iraq. He is one of the youngest vice-presidential nominees in US history.

Mr Vance and Trump will face the Democratic nominees, President Joe Biden and Vice-President Kamala Harris, at the 5 November general election.

The Biden campaign said that Trump picked Mr Vance "because Vance will do what [Trump's former Vice-President] Mike Pence wouldn't ... bend over backwards to enable Trump and his extreme MAGA agenda, even if it means breaking the law and no matter the harm to the American people".