Ukraine and Russia took a technical pause in their peace talks, Ukrainian Presidential Advisor Mykhailo Podolyak, also a member of the delegation, said Monday.

"A technical pause has been taken in the negotiations until tomorrow. For additional work in the working subgroups and clarification of individual definitions," Podolyak tweeted.

Earlier in the day, Podolyak said that the talks between Ukraine and Russia went on, although they were "hard."

The fourth round of negotiations between Ukrainian and Russian delegations was held earlier on Monday via video link.