Cleveland: Freshly crowned Republican presidential nominee Donald Trump tried Wednesday to draw a line under a plagiarism scandal that has rocked his campaign, with a staffer offering to resign.

Having prevailed in his remarkable run to the Republican White House nomination, Trump turned to his next task of quieting questions about his campaign's professionalism and healing crippling party divisions.

A Trump staffer admitted to using Michelle Obama quotes in a speech delivered by Melania Trump at the Republican convention, apologizing and offering to resign over the plagiarism row -- an offer however rejected by the nominee.

Melania Trump had "always liked" the current first lady and had "read me some passages from Mrs Obama's speech" over the telephone as examples of what she wanted to tell the convention on Monday, said the staffer, Meredith McIver.

"I wrote them down and later included some of the phrasing in the draft that ultimately became the final speech. I did not check Mrs Obama's speeches. This was my mistake, and I feel terrible for the chaos I have caused," she said.

"No harm was meant."

Trump wasted little time basking in the glow of his historic achievement, flipping the script once again on the Republican National Convention and telling delegates he would see them Wednesday, a day before he officially accepts the nomination.

After a roller-coaster campaign that saw Trump defeat 16 rivals and steamroll stubborn party opposition, the tycoon said it was time to "go all the way" and beat Democrat Hillary Clinton in November.

"This is a movement," he told the delegates via video link.

When the brash real estate mogul came down the escalators of Trump Tower in New York 13 months ago to announce his candidacy, few experts gave him even the faintest chance.

His campaign has defied political norms -- embracing racially inflammatory policies, offending key voting blocs, eschewing big-spending advertising campaigns and relying on saturated media coverage above campaign structure.

"It's unbelievable. It's surreal. I'm so proud of my father," said Trump's eldest daughter and businesswoman Ivanka Trump, often described as his secret weapon.

"He's the ultimate outsider and he did it. We are so proud of him."

- Closing ranks -

Around the convention floor, Trump's victory was far from universally welcomed.

Many delegates clapped politely after his victory, a few angrily walked out or voiced their unease.

But some delegates who supported others in the primaries were already lining up behind Trump.

"Everybody realizes now that the family infighting is over, we do in fact have a candidate, and I would hope that 99 percent-plus of Republicans get behind that candidate moving forward," said Gary Inmon, a Texas delegate bound to Senator Ted Cruz but who is now solidly behind the nominee.

As the last vestiges of Republican resistance were quashed, there were fresh signs that the party establishment had thrown its lot in with Trump in a bid to beat Clinton.

New Jersey Governor Chris Christie led delegates in declaring Clinton "guilty" and encouraged visceral chants of "lock her up."

Speaker of the House of Representatives Paul Ryan, who hesitated to endorse Trump earlier this year, sounded like he was all-in at the convention.

"The Obama years are almost over. The Clinton years are way over," Ryan said. "Two-thousand sixteen is the year America moves on."

The Trump campaign will hope that disdain for Clinton will unite the party and make a series of missteps -- like the plagiarism scandal -- irrelevant.

"The party is unified, we're all here, I will bet you if you polled this place, there is not one vote for Hillary Clinton in this building," former key Trump lieutenant Corey Lewandowski told AFP.

"People are ready for a fundamental and unequivocal change in Washington and the person who is going to bring that is Donald Trump."

- Pence, Rubio, Cruz take the stage -

On Tuesday, Donald Trump Jr, the candidate's eldest son, made a sweeping speech peppered with personal anecdotes that humanized his father.

The married father of five touched on themes of economic inequality and job creation, promised health care for "our most vulnerable citizens" and vowed to improve public education.

As in Melania Trump's speech the night before, similarities were noted between phrases in the junior Trump's keynote and an article published in a conservative publication.

But he was saved from controversy when the author of the May 2 article in American Conservative, FH Buckley, stepped forward to say he had been a principal speechwriter.

"So it's not an issue," Buckley told Time.com.

On Wednesday, another son, Eric Trump, will make the case for his father, while two senators whom Trump vanquished in the primary race, Marco Rubio and Ted Cruz, will also speak.

Trump's vice presidential pick, Indiana Governor Mike Pence, addresses the confab as well.

Clinton wasted no time seeking to capitalize on Trump's party victory.

"Donald Trump just became the Republican nominee. Chip in now to make sure he never steps foot in the Oval Office," she said in a fundraising tweet.

AFP