Republican National Committee Chairman Reince Priebus lauded Donald Trump on Sunday for softening his tone and showing "maturity" as a candidate after several weeks of turmoil within his campaign.

Priebus' patience with Trump was said to be wearing thin after the GOP presidential nominee found himself at the center of several controversies following the Democratic convention last month. But the candidate has swiftly changed the direction of his campaign with the help of a new campaign manager Kellyanne Conway and a new campaign CEO Steve Bannon, Priebus said.

"He's had a great week. I think he's been on message and he's shown maturity as a candidate," the party chief told ABC's George Stephanopoulos.

"I think he's getting into a groove — he likes the new style that he's been producing out on the campaign trail," Priebus added.

Because of the changes Trump has made, Priebus predicted that polls showing Trump trailing Hillary Clinton in a number of battleground states will soon even out.

Trump delivered a major speech about his economic agenda last week and later shocked his critics by apologizing at a rally in North Carolina for offensive comments he's made during his campaign.

"Sometimes, in the heat of debate and speaking on a multitude of issues, you don't choose the right words or you say the wrong thing. I have done that. And believe it or not, I regret it," he said on Thursday.