Donald Trump’s push for a Ukraine-Russia peace deal to be reached by the end of this week is unrealistic, experts say.

Russian President Vladimir Putin held talks with U.S. President Donald Trump’s special envoy Steve Witkoff in Moscow on Wednesday, the Kremlin said, days before the White House’s deadline for Russia to reach a peace deal with Ukraine or potentially face severe economic penalties that could also hit countries buying its oil.

The two sides agreed to have a prisoner exchange of 1,200 people, National Security and Defense Council Secretary Rustem Umerov said.