Leaders of Germany's Greens may drop demands for a 2030 deadline to phase out combustion engines and shut coal-fired power stations as Chancellor Angela Merkel's government-building efforts intensify.

Merkel's conservatives, the pro-business Free Democrats and the Greens want to determine by mid-November whether there's enough common ground for full coalition negotiations. They struggled to bridge differences during initial talks.

Greens co-leader Cem Ozdemir signaled in an interview with the daily Stuttgarter Zeitung published Tuesday that his party will soften its much-criticized demand to stop registering new cars with gas and diesel engines in 2030. He acknowledged the Greens alone can't push it through.

The party also wants to switch off coal-fired electricity plants by 2030, but chairwoman Simone Peter told the Rheinische Post daily it is "pragmatic" on that issue.