Transcript for British PM Theresa May Visits the White House
President trump making headlines around the world after his first press conference. And Britain's prime minister not afraid to draw the line. Teresa may saying what the president promised her about nato. She made it clear where he stands on Russia and Russian sanctions, and on torture. The British prime minister saying, we condemn torture. Here's Jonathan Karl, leading us off. Reporter: For president trump, his first moment on the world stage. Showing off the bust he returned to the oval office. It's a great honor to have Winston Churchill back. Reporter: The two briefly joined hands as they walked through the colonnade. Today the United States renews our deep bond with Britain, military, financial, cultural, and political. We have one of the great bonds. We pledge our lasting support to this most special relationship. Reporter: And the prime minister showed she knows how to connect with Donald Trump. I'm delighted to be able to congratulate you on what was a stunning election victory. Reporter: But she was also firm on issues where trump has worried the British including nato, which he had previously called obsolete may said trump reassured her he's now a firm supporter. We are united in our recognition of nato as the bulwark of our collective defense, and today we've reaffirmed our unshakeable commitment to this alliance. Mr. President, I think you confirmed that you were 100% behind nato. Reporter: And on the U.S. And European sanctions imposed after Russia invaded Ukraine, the white house has suggested they could be lifted. Not Theresa may. We believe the sanctions should continue. Reporter: President trump is speaking with Vladimir Putin tomorrow. Today he said he hopes they have "A fantastic relationship," but -- I have had many times where I thought I would get along with people, and I don't like them at all. I've had some where I didn't think I was going to have much of a relationship, and it turned out to be a great relationship. So, Theresa, we never know about those things, do we? Reporter: From the British press, tough questions on some of the things that have made Donald Trump so controversial in Europe. Mr. President, you said before that torture works, you have praised Russia. You said you wanted to ban some muslims from coming to America. You've suggested there should be punishment for abortion. For many people in Britain, those sound like alarming beliefs. What do you say to our viewers at home who are worried about some of your views and worried about you becoming the leader of the free world? This was your choice of a question? There goes that relationship. Reporter: On torture, president told David he absolutely thinks it works. But today the commander in chief promised to defer to his new defense secretary, retired general Mattis, who firmly opposes torture. He has stated publicly that he does not necessarily believe in torture or waterboarding. I don't necessarily agree, but I would tell you that he will override because I'm giving him that power. So I'm going to rely on him. I happen to feel that it does work. I've been open about that for a long period of time. But I am going with our leaders. And Jon, there's also news, the president calling for extreme vetting of people coming into the United States? Reporter: This, white house officials say is keeping the promise of having extreme vetting of those coming from countries with a history of ties to terrorism. We're still waiting for details on how that will work.
This transcript has been automatically generated and may not be 100% accurate.