US Defense Secretary Ash Carter says a key Persian Gulf ally has agreed to send special forces soldiers to Syria to assist in the development of local Sunni Arab fighters focused on recapturing Raqqa, the Islamic State group’s capital.

Carter made the comment after meeting Friday at his Brussels hotel with his counterpart from the United Arab Emirates.

Carter declined to say how many Emirati special forces would go to Syria. He said they would be part of an effort led by the United States and bolstered by Saudi special forces to train and enable local Arab fighters who are motivated to recapture Raqqa.

The US war plan for fighting the Islamic State in Syria and Iraq is designed to unseat the extremists in Raqqa and Mosul, which is the group’s main stronghold in northern Iraq.

US Secretary of Defense Ash Carter speaks during a media conference at NATO headquarters in Brussels on Thursday, February 11, 2016. (AP/Virginia Mayo)

US Secretary of Defense Ash Carter speaks during a media conference at NATO headquarters in Brussels on Thursday, February 11, 2016. (AP/Virginia Mayo)

The comments came as Russian Prime Minister Dmitry Medvedev warned other nations against committing their troops to a ground action in Syria, saying it would only exacerbate the conflict.

Medvedev, speaking in an interview with the German newspaper Handelsblatt, the text of which was released by his office Friday, said “a ground operation draws everyone taking part in it into a war.”

Commenting on a Saudi proposal to send troops to Syria and the possibility of US involvement in ground action, Medvedev said there wouldn’t be a quick victory, rather a “permanent war.”

Russian Prime Minister Dmitry Medvedev chairs a meeting with ministers and top officials on social and economic policy in Moscow, on February 10, 2016. AFP PHOTO / SPUTNIK / YEKATERINA SHTUKINA)

Russian Prime Minister Dmitry Medvedev chairs a meeting with ministers and top officials on social and economic policy in Moscow, on February 10, 2016. AFP PHOTO / SPUTNIK / YEKATERINA SHTUKINA)

He reaffirmed that Russia, which has conducted an air campaign in Syria since September 30 to back Syrian President Bashar Assad, has no intention to engage in ground action.

Diplomats meeting in Munich, Germany fell short early Friday in organizing a truce in the Syrian civil war but agreed to try to work out details and implement a temporary “cessation of hostilities” in a week’s time.

The foreign ministers from the International Syria Support Group managed to seal an agreement to “accelerate and expand” deliveries of humanitarian aid to besieged Syrian communities beginning this week.

Carter said the US military will not participate in those aid deliveries.

Carter told reporters that however the proposed suspension of Syrian civil war hostilities is implemented, the US will continue combating IS in Syria.

“There is no cease-fire in the war against ISIL,” Carter said. “Let’s be clear about that.”

US and Russia are to lead a working group meeting Friday to work out aid delivery details.

US Secretary of States John Kerry, right, gestures beside of Russian Foreign Minister Sergei Lavrov during a news conference after the International Syria Support Group meeting in Munich on February 12, 2016. (AFP / Christof STACHE)

US Secretary of States John Kerry, right, gestures beside of Russian Foreign Minister Sergei Lavrov during a news conference after the International Syria Support Group meeting in Munich on February 12, 2016. (AFP / Christof STACHE)

The West has been trading barbs with Moscow over its bombing campaign in the opposition-held city of Aleppo, which observers say has killed 500 people since it began on February 1.

A first round of talks between the Syrian government and the opposition in Geneva collapsed earlier this month over the attacks on Aleppo.

The rebels say they will not return to talks, pencilled in for February 25, unless government sieges and air strikes end.

Germany on Friday put the onus for ceasing fighting primarily on Russia, which Berlin accused of scuppering peace talks through its military offensive.

Syrian government forces raise their weapons as they patrol after taking control of the village of Kiffin, on the northern outskirts of the embattled city of Aleppo on the road leading to Gaziantep, from opposition forces on February 11, 2016. (AFP / GEORGE OURFALIAN)

Syrian government forces raise their weapons as they patrol after taking control of the village of Kiffin, on the northern outskirts of the embattled city of Aleppo on the road leading to Gaziantep, from opposition forces on February 11, 2016. (AFP / GEORGE OURFALIAN)

“The words must be followed with deeds. And here the government puts Russia first under the obligation to do so,” said Christiane Wirzt, government spokeswoman.

Five years of conflict have killed more than a quarter-million people, created Europe’s biggest refugee crisis since World War II and allowed the Islamic State to carve out its own territory across parts of Syria and neighboring Iraq.

Overall, the United Nations says almost half a million people are besieged in Syria. Since the beginning of 2015, Syria’s government had approved just 13 inter-agency aid convoys, out of 113 requested, the UN reported last month.

The failure to agree on a cease-fire leaves the most critical step to resuming peace talks unresolved. It was not clear from their comments afterward if deep differences regarding the truce and which groups would be eligible for it could be overcome.

Secretary of State John Kerry, however, defended the agreement on Friday afternoon.

“They wanted it called and defined as a cessation of hostilities. That is very much in line with their thinking and their hopes,” he said.

Speaking for the group earlier, Kerry hailed the results as a significant accomplishment but noted that a cessation-of-hostilities agreement, if it can be achieved, would only be a “pause” in fighting and that more work would need to be done to turn it into a fully-fledged cease-fire.

He also allowed that the agreements made were “commitments on paper” only.

“The real test is whether or not all the parties honor those commitments and implement them,” he told reporters after the nearly six-hour meeting at a Munich hotel, which ran into the early hours of Friday.

Russia had proposed the March 1 cease-fire date, which the U.S. and others saw as a ploy to give Moscow and the Syrian army three more weeks to try to crush Western- and Arab-backed rebels. The US countered with demands for an immediate stop to the fighting.

Despite apparent concessions on potential timing of the truce and the agreement to set up the task force, the US, Russia and others remain far apart on which groups should be eligible for it. At the moment, only two groups — the Islamic State and the al-Qaeda-affiliated al-Nusra Front — are ineligible because they are identified as terrorist organizations by the United Nations.

Russia, Syria and Iran argue that other groups, notably some supported by Turkey, Saudi Arabia and other Arab states, should not be eligible for the cease-fire, and there was no sign Friday that those differences had been resolved.

Lavrov said the Russian air campaign in support of Assad’s military would continue against terrorist groups and denied persistent reports that the Russian strikes have hit civilian areas, notably around rebel-held Aleppo, where heavy fighting has been raging for the past week.

Asked Friday to comment on the Munich talks, Salem Meslet, the spokesman for the Syrian opposition coalition known as the High Negotiations Commitee, said, “We must see action on the ground in Syria.”