"There has not been any real engagement," said ambassador James Jeffrey, the US special envoy for Syria and the coalition against the Islamic State.

"Our position, as you know -- we've said it several times -- is that we're prepared to discuss with the Iraqi government our overall strategic relationship," Jeffrey told reporters.

"We have a Strategic Framework Agreement with Iraq since 2008," he said. "It covers economic, security, and diplomatic engagement across the board.

"We see this as a package," Jeffrey said. "And when we do sit down and talk with them, that's where we'll be aiming to direct the conversation."

Jeffrey said that operations against IS fighters have been on hold since a January 3 US drone strike near Baghdad airport killed top Iranian general Qasem Soleimani.

The killing of Soleimani prompted retaliatory strikes from Tehran on an Iraqi base hosting US troops and a vote in Iraq's parliament for the removal of foreign forces.

"Coalition operations have been primarily on pause in Iraq as we focus on force protection and looking into the way forward with the Iraqi government after the non-binding vote by the Council of Representatives on the withdrawal of US and thus coalition forces," Jeffrey said.

The special envoy said there had been no notable surge in IS activities in Iraq since Soleimani's killing.

"We have not seen an uptick in violence in Iraq," he said. "They haven't taken advantage of it, as far as we can see."

Jeffrey said US operations against IS would not remain on hold forever.

"There is a possibility of a degradation of the effort against Daesh if we're not able to do the things that we were doing so effectively up until a few weeks ago," he said.

"We're not keeping thousands of Americans and thousands of other coalition country troops in Iraq without doing something," he said. "We have a mission, it's an important mission."