Republican presidential candidate Donald Trump has chosen Mike Pence, governor of the central US state of Indiana, as his vice-presidential running mate, Trump announced Friday.
"I am pleased to announce that I have chosen Governor Mike Pence as my Vice Presidential running mate," Trump said on Twitter, adding the pair will hold a press conference Saturday.
Pence described himself on Twitter as "honoured" to join Trump and "work to make America great again."
Trump had been scheduled to announce his vice-presidential candidate at an event Friday, but delayed it in the wake of the Bastille Day attack in Nice.
Some US media had reported Thursday that Pence would be chosen, but the Trump campaign had said no choice had been made prompting speculation that the candidate may have changed his mind.
Pence, 57, has served as governor of Indiana since 2013 and also represented the state in Congress for more than a decade.
Trump has signalled that he wants an experienced lawmaker to help his presidential ticket because he is a political outsider with no experience in governing.
Pence is seen as a fiscal and social conservative who can appeal to a broad swathe of voters in the centre-right party in a bid by Trump to make himself more palatable to some Republicans who have been wary of his candidacy.
Pence's low-key persona stands in contrast to Trump, but Pence will likely do little expand support among critical swing voters with economic and social positions that have little appeal beyond the party's base.
Trump met Wednesday in Indiana with Pence, as he has done with other candidates he has said are his top choices. Trump himself had said that Pence was among his top picks, along with New Jersey Governor Chris Christie and former speaker of the House Newt Gingrich.
Pence points to his work enacting the largest tax cut in state history and lowering business taxes, balancing the state's budget and efforts to draw businesses to the state.
Conservative groups welcomed the move.
"His Reagan-esque approach, as a great communicator with the courage of his convictions, sends the signal to conservatives across America that Donald Trump is eager to bring Americans together to reject Hillary Clinton's plans to continue President Obama's radical agenda," said Matt Schlapp, chairman of the American Conservative Union.
As governor, Pence came under fire after signing a so-called religious freedom bill that opponents said would have allowed businesses to discriminate against gays, but he later revised the legislation.
The campaign of Democrat Hillary Clinton sought to portray Pence as an extreme choice with long-standing ties to the conservative Tea Party wing of the Republican Party.
"By picking Mike Pence as his running mate, Donald Trump has doubled down on some of his most disturbing beliefs by choosing an incredibly divisive and unpopular running mate known for supporting discriminatory politics and failed economic policies that favour millionaires and corporations over working families,” campaign chairman John Podesta said.
Gay rights groups also denounced Pence and said it demonstrated Trump's anti-gay agenda, despite the billionaire businessman's past statements reaching out to the community.
"Mike Pence has never left any question about his animus toward LGBTQ people, from peddling a hateful and damaging 'right to discriminate bill' in Indiana last year, to his longstanding opposition to marriage equality - positions shared by Donald Trump," said Human Rights Campaign President Chad Griffin.
Pence has disagreed prominently with Trump on a number of issues, including speaking out against the Republican presidential candidate's controversial call for a ban on Muslims entering the United States and on trade deals.
Pence had been in a tight re-election bid for governor and faced a Friday deadline to withdraw from that race in order to run for vice president instead.