Trump vows 'America first' foreign policy

Rolling out an "America first" foreign policy, Republican front-runner Donald Trump vowed on Wednesday that if he were elected president, US allies in Europe and Asia would have to fend for themselves if they did not pay more for the US defense umbrella.

Trump's speech, delivered with a teleprompter in a staid Washington hotel ballroom, was an attempt to show he can be more presidential and move past the rancorous rhetoric that he routinely uses on the campaign trail.

"My foreign policy will always put the interests of the American people, and American security, above all else. That will be the foundation of every decision that I will make," Trump said. "'America first' will be the major and overriding theme of my administration."

The New York billionaire spoke the day after victories in five Northeastern states that moved him closer to capturing the Republican Party nomination for the Nov 8 election.

But the message Trump delivered appeared contradictory at times and was largely devoid of details.

While issuing that stern message on paying for defense, Trump said the United States under his leadership would be "a reliable friend and ally again."

Trump was sharply critical of immediate past presidents, both Republican and Democratic, for getting Americans involved in military conflicts abroad, but said the United States may well need to use force to defeat Islamic State militants.

In perhaps his most specific policy prescription, Trump said he would organize two summits, for Nato allies and Asian allies, to discuss "rebalancing" the alliances to ease the financial burden to the United States.

Clinton adviser Madeleine Albright, herself a former secretary of state, said Trump's address was centered on "simplistic slogans and contradictions."

Jon Alterman, director of the Middle East program at the Center for Strategic and International Studies think tank in Washington, said Trump's speech did not contain enough details to call it a strategy. "Ultimately, he's selling a dream and he's still not offering a plan. He's representing the sales office, but he's given no clue of who will be the architect and who will do the construction," he said.