US President Donald Trump said on Friday that Washington was in "very deep" negotiations with Hamas and urged them to release all hostages held in Gaza. "We are in very deep negotiation with Hamas," Trump told reporters, saying the situation will be "tough" and "nasty" if Hamas continues to hold Israeli hostages. "We said let them all out, right now let them all out. And much better things will happen for them but if you don't let them all out, it's going to be a tough situation, it's going to be nasty," Trump said, adding that Hamas was "asking for some things that are fine." Trump did not elaborate further.