A May 21 meeting of the all-Ukrainian national unity roundtable, announced by Donetsk region administration head Serhiy Taruta, is believed to have been postponed, a region administration source told Interfax-Ukraine.

The agency has so far been unable to obtain official confirmation of the report.

However, Donetsk Mayor Oleksandr Lukianchenko has said he knows nothing of any plans to hold a "national unity roundtable" in Donetsk on May 21, the OstroV news Web site reported.

"I know nothing about it," the mayor told reporters on Tuesday.