He says he has “every expectation” the alliance will assume full command, instead of enforcing only the no-fly zone and the arms embargo.
Coalition forces are into a seventh day of military action over Libya to enforce the UN resolution.
Mr Hague insisted there was no split in the international community.
“If the Gaddafi regime think the international will and unity on this is faltering in any way, they are in for quite a surprise,” he said.
Mr Hague said a conference in London on Tuesday, which will include Arab nations alongside the EU and the US, would lock in commitments of military and financial support which he said were “increasing all the time”.
Prime Minister David Cameron also told a news conference at the EU summit in Brussels that Nato would shortly be providing command and control for the operation.
Dismissing talk of a split within Nato, he explained: “These things always take a bit of time.”