Ukraine's President Petro Poroshenko has said that the Special Monitoring Mission (SMM) of the Organization for Security and Co-operation in Europe (OSCE) is still being impeded in conducting its monitoring in Donbas.

"The OSCE SMM, which does ceasefire monitoring and verification, encounters limitations during its work in the areas controlled by armed formations. These forbid [monitors] from visiting the places where heavy weapons had been seen in violation of the relevant agreements," he told the media before his talks with German Chancellor Angela Merkel in Berlin on Monday.

Besides, the head of Ukrainian state said that OSCE SMM mission can't reach a part of Russia-Ukraine border that is beyond Ukraine's control.

"OSCE SMM by now has no opportunity to visit uncontrolled part of the Ukrainian-Russian border," he said.