Trump accepted the nomination on Thursday evening, portraying himself as a friend of the working class and the candidate to restore law and order.

"Friends, delegates and Americans, I humbly accept your nomination for the president of the United States," he said.

"Together we will lead our party back to the White House and we will lead our country back to safety, prosperity and peace. We will be a country of generosity and warmth, but we will also be a country of law and order."

The property billionaire highlighted recent instances of civil unrest in the US and the shootings of police officers, he also confidently predicted that "safety would be restored" when he became president.

"Americans watching this address tonight have seen the recent images of violence in our streets and the chaos in our communities," said Trump, confidently adding that things would change when he became president. "I have a message for all of you: the crime and violence that today afflicts our nation will soon come to an end."

Trump also argued that the US had lost its standing in the world, and promised to address the issue.

"As long as we are led by politicians who will not put America first, then we can be assured that other nations will not treat America with respect," said Trump. "This will all change when I take office."

"My message is that things have to change - and they have to change right now."

The 70-year-old's sweeping acceptance speech lasted 75 minutes, and included issues such as the US trade deficit, racial divisions within America and Democratic nominee Hillary Clinton's record as Secretary of State.

Former Democratic presidential hopeful Bernie Sanders questioned Trump's assertion that he would tackle the country's problems "alone," rather than together with Congress.

Ivanka introduces father

Immediately ahead of the speech, Trump's daughter Ivanka spoke about her father's personal qualities and compassion. "When my father says he will make America great again, he will deliver."

"When you have my father in your corner, you will never again have to worry about being let down."

There was also a speech from PayPal cofounder Peter Thiel, who became the first delegate to reference his sexuality in an address at a Republican convention. German-born Thiel said he was proud to be gay, but did not make an expected appeal for the Republican Party to adopt a more gay-friendly platform.

Earlier in the day, Trump faced criticism after suggesting that the US might abandon its NATO military commitments if he were elected president. Trump had said he might seek to scrap the alliance's guarantee of mutual defense if other members failed to fulfill their NATO obligations.

Reaction is harsh

Despite thunderous applause on the convention floor, Trump remains a divisive figure even within his own part. Senator Ted Cruz of Texas was jeered by thousands of delegates on Wednesday night when he took the stage and pointedly failed to endorse his former rival.

Several top party officials - included former and current elected officials - also skipped the convention, highlighting divisions.

Meanwhile, Democratic presidential hopeful Hillary Clinton's campaign dismissed the speech as painting "a dark picture of an America in decline" and questioned Trump's fitness to serve as president.

"He offered no real solutions to help working families get ahead or to keep our country safe, just more prejudice and paranoia," Clinton's campaign chairman, John Podesta, said in a statement. "America is better than this. America is better than Donald Trump."

And John Weaver, a Republican Party strategist who had advised Trump's rival Ohio Governor John Kasich, said in a tweet that Trump had delivered the "darkest" acceptance speech in modern history.

Despite Trump's tepid attempts at reaching out to gay, lesbian and transsexual voters, organizations like the Human Rights Campaign which lobbies for gay rights in the US were unimpressed.

"His hatred toward anybody is a huge concern," said Jay Brown of the Human Rights Campaign. "When he attacks women, he attacks us. When he attacks Muslims, he's attacking us."

rc,jar/gsw (AP, AFP, dpa, Reuters)