Donald Trump accepts Republican nomination for US president

New York billionaire Donald Trump on Thursday formally accepted the Republican Party nomination for president, vowing to defeat Hillary Clinton in November and claim victory in the US general election.

"I humbly and gratefully accept your nomination for the presidency of the United States," he said to a standing ovation and chants of "USA, USA, USA" at the Republican National Convention.

"Together, we will lead our party back to the White House," he told the giant sports arena in Cleveland, vowing to get tough faced with the recent shootings and attacks that have rocked the country.

"I have a message for all of you: the crime and violence that today afflicts our nation will soon come to an end. Beginning on January 20th 2017, safety will be restored," he said.

His speech caps an extraordinary campaign that defied political norms and marked a stunning primary victory for a former reality TV star and real estate mogul who has never previously held elected office.