Trump hedges on NATO protection

Republican nominee Donald Trump has hinted at a new world order if he becomes president, saying under his leadership the US might not come to the defense of some NATO members if Russia were to attack them.

Trump said he would decide whether to protect the Baltic republics against Russian aggression based on whether those countries "have fulfilled their obligations to us."

He made the comments in an interview with The New York Times ahead of his speech to formally accept the Republican nomination for president on Thursday.

NATO, or the North Atlantic Treaty Organization, is a military alliance of European and North American democracies created after World War II to strengthen international cooperation as a counter-balance to the rise of the Soviet Union.

Presumptive Democratic nominee Hillary Clinton's campaign was quick to pounce on Trump's statements.

"The president is supposed to be the leader of the free world. Donald Trump apparently doesn't even believe in the free world," Clinton senior policy adviser Jake Sullivan said in a statement shortly after the interview was published.

Trump's running mate, Governor Mike Pence, was on the defensive, telling Fox News that he is confident the Republican nominee would stand by America's NATO allies, but insisted that those countries "must pay their fair share."

Trump also told The Times that he would not criticise Turkey for cracking down on political opponents and restricting civil liberties following last week's attempted coup.

Of Turkish President Recep Tayyip Erdogan, Trump said: "I give great credit to him for being able to turn that around."