After Donald Trump declined to endorse Paul Ryan ahead of the House speaker's primary election later this month, Trump campaign chairman Paul Manafort weighed in on the GOP nominee's decision Thursday.

Asked on "CBS This Morning" what it would take for Trump to back Ryan, Manafort insisted that "there's no issue" about it.

"He's going to support Paul Ryan," the campaign chief said. "I mean, he does support Paul Ryan. He said he's going to work with Paul Ryan."

"He didn't take a position in the primary, he didn't take a position in many primaries," Manafort continued. "That's not the news. The news is the two of them working together to elect a Republican Congress and a Republican president, and I think you're going to see that."

Ryan, despite his own endorsement for Trump earlier this year, has continued to be a vocal critic of Trump's policies and inflammatory rhetoric. Just this week, Ryan stood by the Gold Star Khan family, who lost their Army captain son in the Iraq War, after the Republican nominee accused them of "viciously" attacking him.

Manafort also discussed Trump's vice presidential nominee, Mike Pence, and the Indiana governor's choice to endorse Ryan.

"Paul Ryan is a close personal friend of Mike Pence," he said. "Donald Trump understood that relationship."

When pressed, as a lifelong Republican, on his own views of Ryan, Manafort at first declined to elaborate.

"Look, I'm chairman of the campaign and as chairman of the campaign we have a campaign position of not getting involved in primaries," he said.

But later, he added in a seeming slip of the tongue: "I support him as a speaker and I know after next week I'm going to be supporting him as a candidate for president too -- I mean..."

Manafort chuckled at that, as "CBS This Morning" hosts noted the rumors and the "talk" around the possibility that Trump may drop out of the race ahead of the election.

The campaign chief also weighed in on his candidate's dipping poll numbers following the Democratic party's national convention.

"The dropping poll numbers were expected," Manafort said. "We feel as though in a week or so the polls are going to even out. We always thought that. We had a bounce, we knew that the Democrats would have a bounce."

Asked if his candidate's tendency at rallies to veer off message and litigate old campaign controversies (like Trump's feud with Fox News anchor Megyn Kelly) hurts their chances in November, Manafort seemed to blame the media for its coverage of Trump's speeches.

"Well, the thing is, you nitpicked what he says, and the other day he was talking about, strong message, on what's going on with this $400 million in Iran, which is an outrageous amount of money," Manafort said, referencing a cash payment made to Iran that the White House claimed was to settle an outstanding legal dispute from decades back.

"There's a responsibility on both parts -- the media and the campaigns," he said. "Everybody understood what the real messages were in that speech. He was talking about the Iranian situation, he was talking about the cash, he was talking about the decisions."

Manafort added that the campaign feels "confident" that the issues are being heard locally.

Despite Trump's recent slip in the polls, Manafort said "there's plenty of time" to bounce back.

"We're in the first week of August," he said. "Usually campaigns don't even start until September. We're using August as a very aggressive month, however."