Rob Portman's (R-OH) re-election bid.
House of Representatives Speaker Paul Ryan, the top USA elected Republican, was to formally put Trump's name forward later on Tuesday to be the party's presidential nominee for the November 8 election.
Manafort made similar comments on other TV programs.
During the afternoon session, those opponents shouted "Call the roll, call the roll", as Trump supporters and party loyalists chanted back "USA!"
Melania, who became an American citizen in July 2006, called the experience "the greatest privilege on planet Earth". Republicans are trying to focus on defeating presumptive Democratic presidential nominee Hillary Clinton and protecting the United States and its troops overseas from terrorism.
Daughter Ivanka Trump will introduce her father on Thursday, the convention's final day.
Iowa's Republican Party Chairman, Jeff Kaufmann, said the top issue a month ago for voters in the state was the economy.
Cleveland: The Republican convention, which will formally coronate controversial billionaire Donald Trump as the party's presidential candidate and project his "different and new image", will kick off here amid tight security and heightened tensions following a series of shootings in the US.
Paul Manafort says in an interview on MSNBC's "Morning Joe" that Kasich is "hurting his state, he's embarrassing his state, frankly" by skipping the four-day event convened to nominate Trump for president.
Still, there was a silent protest, of sorts, in the many GOP luminaries who are avoiding the convention stage or Cleveland altogether, wary of being linked to a man whose proposals and temperament have sparked an identity crisis within the party.
"I was expecting a lot more people", said Shanisha Hunter, 32, who traveled from NY to demonstrate.
Melania Trump received several standing ovations during her speech.
The convention then approved the party policy platform and took a scheduled break before a lineup of evening speakers also due to include Trump's wife, Melania, and former New York Mayor Rudy Giuliani.
Her speech displayed Trump's softer side, oft shielded and secret from the press that constantly follow him.
Melania appeared at the RNC Tuesday night and delivered a moving speech to roar up the crowd.
Christie told reporters Sunday night that he didn't lobby for the position and was honored to be considered. The Republican National Convention starts Monday, in Cleveland.
The short-lived chaos on the convention floor underscored that the Republican Party's effort to unite behind its often-divisive leader has fallen short.
Trump, a billionaire NY businessman who also made his mark as a reality TV star, brought out some big guns from the entertainment world.
Yet the first act Monday was likely to underline how divisive Trump has been.
Now he's challenging the rules at the GOP convention in the hopes that all delegates can vote for whomever they choose.
The normally highly choreographed proceedings inside the Quicken Loans Arena in Cleveland, veered off the rails abruptly when the chair at its first session on Monday afternoon, U.S. congressman Steve Womack, called a shouted vote to approve or deny the motion for such a floor vote on a rules change.