Donald Trump has raised new questions about his commitment to the defense of NATO allies on the eve of his acceptance of the Republican presidential nomination, The New York Times reported.
In an interview with the newspaper on Wednesday, Trump also expressed little willingness to speak out against purges or civil rights crackdowns by authoritarian allies like Turkey, the Times said.
"I don't think we have the right to lecture," the Times quoted him as saying during the 45 minute interview in a downtown Cleveland hotel suite.
"Look at what is happening in our country," he said. "How are we going to lecture when people are shooting policemen in cold blood?"
The Times said that Trump re-emphasized the hardline nationalist approach that he has taken during his campaign, describing how he would force allies to shoulder defense costs that the United States has borne for decades.
Asked about Russian activities that have alarmed the Baltics, NATO's newest members, Trump said that if Russia attacked them, he would decide whether to come to their aid only after reviewing whether those nations "have fulfilled their obligations to us."
"If they fulfil their obligations to us, the answer is yes," he said.
A cornerstone of the 28-member trans-Atlantic alliance is its Article 5 commitment that an attack one member state is an attack on all, a pledge invoked after the September 11, 2001 attacks on the United States.
Estonian President Toomas Hendrik Ilves was quick to fire back on Twitter Thursday, insisting that his nation of 1.3 million people bordering Russia is meeting all its NATO spending commitments.
"Estonia is 1 of 5 NATO allies in Europe to meet its 2 percent defence expenditures commitment," he said, adding Estonians had "fought, with no caveats" in NATO operations in Afghanistan.
"We are equally committed to all our NATO allies, regardless of who they may be. That's what makes them allies," Ilves said.
Trump, who said he would press the theme of "America First" at his address Thursday night to the Republican National Convention, said allies would adjust to his approach.
"I would prefer to be able to continue" existing agreements, he told the Times, but only if allies stop taking advantage of an era of American largesse that was no longer affordable.
The remarks also drew fire from presumptive Democratic nominee Hillary Clinton's campaign, which said they showed Trump "is temperamentally unfit and fundamentally unprepared to be our commander-in-chief."
"It is fair to assume that Vladimir Putin is rooting for a Trump presidency," said Clinton foreign policy adviser Jake Sullivan.