Obama speaks about recent Northern Ireland troubles

"I want everyone listening to know this - the United States will always stand with those who work towards peace," he said.

The murders earlier this month by dissident republicans of a police officer and two soldiers in the space of three days has placed renewed international focus on Northern Ireland.

President Obama said the "real question" was how the people of Northern Ireland would respond following the killings.

"Now we know the answer - they responded heroically. They and their leaders on both sides have condemned this violence and refrained from the old partisan impulses," he said.

"They've shown they judge progress by what you build and not what you tear down. And they know that the future is too important to cede to those who are mired in the past."

President Obama also met Northern Ireland's first and deputy first ministers Peter Robinson and Martin McGuinness in the office of his national security adviser.

Mr Robinson said he believed both he and the deputy first minister had reassured Americans about the prospects for investment following the recent dissident republican murders.

He said that several US businesses were looking to relocate to Northern Ireland.

Mr McGuinness said "the dissidents' strategy would never unite Ireland in a million years".