The US envoy for Syria James Jeffrey has asked the German government to commit ground troops to support the Kurdish-led Syrian Democratic Forces (SDF) in Syria, easing the burden on Washington, according to Welt am Sonntag and the DPA newswire.

The demand was communicated to foreign minister Heiko Maas during a visit to Iraq in June.

The German constitution would require parliamentary consent to commit ground troops, which is unlikely to be granted by Angela Merkel’s junior coalition partners, the Social Democrats. Given similar resistance from the Greens and the Left party, Germany is politically unable to provide the support Washington requires.

On Monday, the government’s spokesman, Steffen Seibert, formally rejected US demands.

“When I say that the government intends to continue with its ongoing measures in the framework of the anti-IS coalition, then that means no ground troops,” Seibert said.

Germany is committed to the campaign against the Islamic State with reconnaissance jets, a refueling aircraft and non-combat military assistance. German military assistance was due to expire in October. According to the foreign ministry, the government is willing to extend the duration of the Syrian mission, but not to widen its scope to include ground troops.