Germany’s defense minister has told lawmakers she wants to get the UN Security Council to approve a safe zone in northern Syria, Reuters cited a source as saying on Wednesday.

Annegret Kramp-Karrenbauer said NATO partners had signaled readiness to discuss her proposal, which was made public on Monday, according to two sources.

The minister, who is Angela Merkel’s preferred successor as chancellor, said earlier she did not rule out sending German soldiers to Syria, but that would be a matter for parliament.

The proposal raised tension in Merkel’s coalition as the SPD party is wary of foreign military commitments.