Secretary of Defense James Mattis dispelled reports Tuesday that he was apprehensive about working with President Trump’s incoming National Security Advisor John Bolton.

"I'll tell you right up front, it's going to be a partnership, we are going to go forward," Mattis told reporters during a news conference at the Pentagon.

When asked about his differing world views with Bolton, Mattis responded, "I hope that there's some different world views. That's the normal thing you want unless you want group think."

Mattis acknowledged that the two hadn’t met yet but said Bolton was coming to the Pentagon later this week for discussions.

"We are going to sit down together and I look forward to working with him," Mattis said.

He emphasized that he had no reservations about Bolton’s appointment.

"No reservations, no concerns at all,” he said. “Last time I checked he's an American. I can work with an American, OK? So I'm not the least bit concerned with that sort of thing."

Mattis and Bolton are likely to differ when it comes to the Iran deal. Mattis has advised President Trump to stay in the deal. Bolton, on the other hand, has repeatedly advocated for tearing up the agreement. Trump has a May 12 deadline for deciding whether the U.S. will leave the Iran deal or attempt to renegotiate it.

Another apparent area of disagreement between the two is North Korea. Mattis has advocated for a diplomatic strategy with North Korea, but Bolton recently wrote an op-ed making a case for launching a preemptive strike on North Korea.