In an unusual incident, U.S. President Barack Obama on Friday slapped down a heckling journalist who was furious over his move to stop deporting young illegal immigrants.

The reporter, Neil Munro, of the conservative Daily Caller website, broke into Obama's remarks as he outlined plans to defer deportations of illegal immigrants between the ages of 16 to 30 brought to America by their parents.

"Excuse me, sir. It's not time for questions, sir," Obama said, as he spoke over Munro, who shouted something about the president prejudicing the chances of young American citizens who cannot find work.

Munro then asked whether Obama would take questions and the president replied, "Not while I'm speaking."

Later on in his speech, Obama again took on Munro, who shouted from the back of a row of chairs set up for the president's remarks in the Rose Garden of the White House.

"I didn't ask for an argument. I'm answering your question," he said.

It is highly unusual for Obama, who was clearly annoyed by Munro's disturbance, to be interrupted during formal remarks.

Reporters often shout questions to the president after he has finished speaking, and he frequently chooses to ignore them. (AFP)