WASHINGTON • The United States has turned up the heat on the Islamic State in Iraq and Syria (ISIS) terror group, sending an additional 400 US troops into Syria to support an offensive to retake Raqqa, the militants' de facto capital.
The administration also announced a high-level meeting of the 68 countries in the US-led coalition to discuss plans to accelerate ISIS' defeat.
The troop increase - which includes a team of Army Rangers and a Marine artillery unit that have both already arrived in Syria - represents a near doubling of the number of US troops there.
The US military has declined to say how many troops it has deployed in Syria. The formal cap is 503, but commanders have the authority to temporarily exceed it.
"We are preparing logistical and fire support to enable a successful assault on Raqqa, the self-proclaimed capital of ISIS," said Colonel John Dorrian, a spokesman for the US-led command that is fighting ISIS in Iraq and Syria.
The Rangers' presence became apparent last weekend when they were seen driving around the northern Syrian town of Manbij in Stryker vehicles and armoured Humvees.
Before he left office, President Barack Obama approved the use of a small number of Apache attack helicopters, which are expected to be part of the Raqqa operation as well.
Complicating the US strategy is the fact that Nato ally Turkey is dead set against Raqqa falling to an Arab-Kurdish force under the Syrian Democratic Forces (SDF).
Trained and advised by US special operations troops, the SDF has proved to be the most reliable US ally on the ground in Syria and the only local force it considers capable of rapidly taking Raqqa.
However, Turkey regards the SDF as a cover for the Kurdish YPG militia, branded a terrorist organisation by Ankara.
US-backed Syrian militias said on Thursday that they have enough forces to capture Raqqa from ISIS with support from the US-led coalition, underlining their opposition to any Turkish role in the attack.
US Secretary of State Rex Tillerson will host the coalition's meeting in Washington this month to discuss its next moves fighting ISIS, the State Department said on Thursday.
It's an opportunity for Secretary Tillerson to lay out the challenges that are facing the coalition moving forward... We all recognise that we have seen progress in defeating ISIS on the ground... How do we leverage that success? How do we build on that success?
ACTING STATE DEPARTMENT SPOKESMAN MARK TONER
The meeting of coalition foreign ministers, on March 22 and 23, aims "to accelerate international efforts to defeat ISIS in the remaining areas it holds in Iraq and Syria and maximise pressure on its branches, affiliates and networks", the State Department said in a statement.
It said that this would be the first meeting of the full coalition since December 2014, shortly after it was founded.
"It's an opportunity for Secretary Tillerson to lay out the challenges that are facing the coalition moving forward," acting State Department spokesman Mark Toner told reporters.
"We all recognise that we have seen progress in defeating ISIS on the ground... How do we leverage that success? How do we build on that success?"
President Donald Trump signed an executive order on Jan 28 requesting the Pentagon, the joint chiefs of staff and other agencies to submit a preliminary plan in 30 days for defeating ISIS.
Mr Toner said details of that plan are still classified, declining to provide further information. He said the meeting would look at how "to augment existing capabilities and processes on the ground".
On March 23, after the ministerial meeting, a coalition working group, including military officers, will meet to flesh out plans.
Russia - which has forces on the ground in Syria and has expressed a desire to work with US forces against ISIS, but is not a coalition member - will not be represented.
AGENCE FRANCE-PRESSE, REUTERS, NYTIMES