Baghdad/Arbil: The United States will send more troops to Iraq, potentially putting them closer to the frontlines to advise Iraqi forces in the war against IS militants.
Also on Monday, a member of IS's war council and two aides were killed in northern Iraq on Monday by US and Kurdish commandos in the second helicopter raid in two days in the area by a US-led coalition, Kurdish security sources said.
US Defence Secretary Ash Carter made the announcement on Monday during a visit to Baghdad during which he met US commanders, Iraqi Prime Minister Haider Al Abadi, and Iraqi Defence Minister Khaled Al Obeidi.
About 200 additional troops will be deployed, raising the number of US troops in Iraq to about 4,100, a senior US Defence official said.
The Pentagon will also provide up to $415 million to Kurdish peshmerga military units.
Carter did not meet Kurdish leaders in person during his visit, but spoke with the president of the Kurdish region, Massoud Barzani, on the telephone.
Monday's announcement is the move in the past several months by the United States to step up its campaign against the hardline group. US special forces are also deployed in Iraq and Syria as part of the campaign.
Iraqi forces - trained by the US military and backed by air strikes from a US-led coalition - have since December managed to take back territory from IS, which seized swathes of Iraqi and Syrian territory in 2014.
The new US troops will consist of advisers, trainers, aviation support crew, and security forces. Most of the new military advisers are expected to be army special forces, as is the case with the approximately 100 advisers now in Iraq.
The advisers will be allowed to accompany smaller Iraqi units of about 2,500 troops that are closer to the frontlines of battle, whereas now they are limited to larger divisions of about 10,000 troops located further from the battlefield.
That will allow the US military to offer quicker and more nimble advice to Iraqi troops as they try to retake Mosul, the largest Iraqi city still under IS control.
But by placing them closer to the conflict, it could leave them more vulnerable to enemy mortars and artillery.
The United States has also authorised the use of Apache attack helicopters to support Iraqi forces in retaking Mosul, Carter said.
The United States had originally offered the Apaches to the Iraqi government in December. The Iraqis did not take up the offer then but did not rule out their use.
The United States will also deploy an additional long-range rocket artillery unit to support Iraqi ground forces in the battle for Mosul, Carter said. There are two such batteries already in place in Iraq.
Meanwhile, a statement by the Kurdish regional security council said Monday's raid south of the Iraqi city of Mosul killed Suleiman Abd Shabib Al Jabouri, also known as Abu Saif.
As a member of the militant group's war council, the statement said, he had been responsible for offensives in Makhmour, 80km (50 miles) from Mosul, where an Iraqi army push launched last month has stalled.
In a separate operation on Sunday, troops from a US-led coalition landed a helicopter north of Mosul and seized at least one IS member from a vehicle, witnesses and Kurdish security sources said.
The force quickly took off again with their captive, the sources told Reuters.
"It all happened in less than 10 minutes," said a witness of the raid in Badush district, around 20km (12 miles) northwest of Mosul, the largest Iraqi city still in the hands of IS.
A spokesman for the US coalition could not immediately be reached for comment on the latest raid. He previously declined to confirm or deny reports of the earlier raid.
A news agency that supports IS said the militants had thwarted the earlier raid in Badush.