President Trump welcomed Iraq’s prime minister to the White House for the first time since taking office.

In the past, Mr. Trump said the U.S. should have taken Iraq’s oil. Iraq was included in his original travel ban, though not in the second version. But despite these tensions, the two men will need to work together.

It was a high-stakes meeting Monday, as both leaders need each other’s help to defeat ISIS, reports CBS News correspondent Margaret Brennan. Mr. Trump pledged to accelerate U.S. support, but Prime Minister Haider al-Abadi also said Mr. Trump’s calls to seize Iraqi oil aren’t helpful.

“Did you tell him privately today, ‘Please stop saying that?’” Brennan asked the prime minister.

“Well, I did say ... tell him privately the Iraqi oil was for Iraqis. And anything else is unacceptable. He seems to accept this,” al-Abadi said.

He said Trump’s comments make it “very difficult” for him back home to work politically with the U.S.

“I think for a president or a president-elect to say this, it brings up all these rumors that the U.S. is after the oil or — and things like that. And that can endanger the relationship,” al-Abadi said. “But I think the president understand very well nobody can take Iraqi oil from Iraqis.”

Al-Abadi said that within weeks Iraqi forces will recapture Mosul, the city where ISIS leader Abu Bakr al-Baghdadi declared his caliphate. About 5,000 U.S. forces are providing support on the ground and from the air. The U.S. and Iraq are now negotiating how many will stay.

“Will you allow that number to remain after?” Brennan asked.

“We don’t need that number after Mosul,” al-Abadi said. “After that… I think we are going to draw down the forces to a level which is acceptable, just to perform all of the training and logistical support.”

During their private meeting, al-Abadi thanked Mr. Trump for removing Iraq from his second version of the temporary travel ban.

“At the end of the day, Iraq was a part of the fight against terrorism. A partner with the U.S. To include Iraq in a list, I found it unacceptable,” al-Abadi said. “So for the second round of the executive order, if Iraq was included, I think we would have been forced to do something about it.”

Brennan pointed out al-Abadi seemed very aware of American politics, with the Iraqi leader touching on the importance of building bridges and not walls.

“What did you mean by that comment?” Brennan asked.

“I mean Berlin Wall was built for so many years ago, but it has collapsed. It didn’t succeed in partitioning people. … So I think building walls between nations is not an answer. You have to build bridges between people,” al-Abadi said, adding, “I never think that walls can protect you.”

“When you walk away from that meeting at the White House do you feel like you can trust the credibility of the American president?” Brennan asked.

“Well, we’re working with U.S. system. I mean this is a relationship between Iraq as a country with the U.S. as a country. Regardless of who is in the White House,” al-Abadi said. “So it’s not for me to judge foreign presidents and administration.”