Russian President Vladimir Putin said on Friday that ultimately an agreement would need to be struck to end fighting in Ukraine, nine months after the Kremlin launched its "special military operation" there.

"Trust, of course, is almost at zero... but ultimately, in the end, an agreement will have to be reached," Putin told a summit of regional leaders in the capital of Kyrgyzstan.

"I have said many times that we are ready for these agreements, and we are open (to them)," he added.

Putin comments came in response to remarks from former German chancellor Angela Merkel about the Minsk agreements, negotiated with Paris and Berlin to end fighting between Russia and Ukraine.

Merkel told Die Zeit newspaper that the 2014 accords were an "attempt to give Ukraine time" and that Kyiv had used it "to become stronger".

Putin in Bishkek said he was "disappointed" by Merkel's comments, adding he "always assumed that the government of Germany was acting honestly".

"After such statements, the question becomes: how can we agree? And is there anyone to agree with? What are the guarantees?" Putin said.