"The decision on whether it is possible to go this way will be made in fact within two to three days," Steinmeier said.
The sides of the conflict have to decide whether they will move further along the path of escalation or will try to achieve a truce and a political solution, he added.
Earlier, Ukrainian President Petro Poroshenko said that suggestions of German Chancellor Angela Merkel and French President Francois Hollande on ending the hostilities on Ukrainian southeast may be implemented.
On Thursday, Merkel and Hollande held talks on the Ukrainian conflict with Poroshenko in Kiev.
On Friday, Russian President Vladimir Putin, Merkel and Hollande discussed in Moscow a new plan for settling the crisis in Donbas.
Despite a ceasefire agreement reached by Kiev and eastern Ukrainian independence supporters in September 2014, fighting between the sides continued. The clashes intensified in January.
According to the UN estimates, over 5,000 people have been killed in Ukraine since the beginning of the clashes in April 2014.
