Donald Trump forgot to put pen to paper during a photo opportunity for the press to watch him sign his new executive orders on trade.

The US President announced two new executive orders to improve trade enforcement on Friday but got flustered when questioned about former national security adviser Michael Flynn's plans to testify about colluding with Russia to influence the US election.

Trump moved to leave the Oval Office promptly after promising "some very good results", but his entourage appeared to notice he had forgotten the task at hand and Vice President Mike Pence tried to stop him at the door.

Pence placed his hand on the President's back before notifying him the documents had not been signed.

Trump appears to tell him to bring the official documents to the next room, with Pence scurrying off to collect the papers from the Resolute desk.

Presidents have historically signed executive orders at the desk, allowing media to photograph the orders being officiated.