Donald Trump has detailed his foreign policy in a speech, a day after sweeping to a win in five US primaries.
Mr Trump, the frontrunner for the Republican candidacy in the 2016 presidential race, said he would pursue an "America First" policy.
He called the foreign policy of President Obama's administration "a complete and total disaster".
On Tuesday, Mr Trump called himself the Republican "presumptive nominee" after his primary wins.
He claimed victories in Connecticut, Delaware, Rhode Island, Maryland and Pennsylvania.
While he has used his campaign to outline some of his foreign policy goals, this is the first time he has detailed them in a speech. He used a teleprompter, having previously said no candidate for the presidency should do so.
Earlier, he said the speech would not be a "Trump doctrine", and that he would retain some flexibility to make changes if elected.
Here are some of the main points he has made so far:
Mr Trump supports stronger interrogation of IS suspects
He says that no other candidate would be tougher on the so-called Islamic State (IS) and he would weaken the militants by cutting off their access to oil.
He has also said he supports waterboarding and other strong interrogation methods against IS. And while he says he would stay within the law, he would like laws on interrogation techniques expanded.
On nuclear weapons
The nuclear threat, and the risk of proliferation, is "the biggest problem the world has", Mr Trump told the New York Times last month. Using a nuclear weapon first would be "an absolute last step", he said.
On US allies
Mr Trump has decried what he calls the United States' position of "the world's policeman", and calls it a weakness. He has called for a reassessment of ties with some of Washington's closest allies.
Speaking to the New York Times about the US-Japan relationship, he said: "If we're attacked, they do not have to come to our defence, if they're attacked, we have to come totally to their defence. And that is a, that's a real problem."
On China, for example, he says it should be taken to task on a number of issues in order to make trade with the US more equitable. If elected, he says he will make China stop undervaluing its currency.
Mr Trump once said he was his own best foreign policy adviser, but, in recent months, has expanded his back-room team. Some of his appointments had proved controversial.
The team is led by Republican Senator Jeff Sessions of Alabama who has helped shape Mr Trump's policies.
Another member, retired Gen Joseph Schmitz, resigned from the military in 2005 amid accusations of misconduct. However, Mr Schmitz was never charged with wrongdoing.
Another adviser, Walid Phares, was criticised when he was named as part of Mitt Romney's foreign policy team in 2011.
Muslim advocacy groups took issue with Mr Phares's close ties to right-wing Christian militia groups during the Lebanese civil war.
After his sweep of the five mid-Atlantic states, Mr Trump said of the battle for the Republican nomination: "It's over. As far as I'm concerned, it's over."
He told supporters in New York he would not moderate his policies if elected president.
For the Democrats, Hillary Clinton was denied a clean sweep by Bernie Sanders, after he won in Rhode Island.
After their victories, Mr Trump and Mrs Clinton turned their fire on each other.
Mr Trump said his Democratic rival's only advantage in the presidential race was being a woman.
"Frankly, if Hillary Clinton were a man, I don't think she'd get 5% of the vote," he said.
Mrs Clinton hit back at his accusation that she was playing the "woman card".
"Well, if fighting for women's healthcare and paid family leave and equal pay is playing the woman card, then deal me in," she told cheering supporters in Philadelphia.