EU High Representative for Foreign Affairs and Security Policy Catherine Ashton is continuing diplomatic efforts aimed at de-escalation of the situation in Ukraine, her spokesperson, Maja Kocijancic, said in a statement on Tuesday.

"In this context she will meet foreign ministers of the U.S., the Russian Federation and Ukraine next week," reads the statement.

It also states that Ashton n is following closely the worrying developments in eastern Ukraine, including seizure of public buildings in Kharkiv, Donetsk and Luhansk with use of force. The EU foreign policy chief also commends the Ukrainian authorities for pursuing their law and order operations in a measured manner.

"The High Representative reiterates the strong support of the European Union for Ukraine's unity, sovereignty and territorial integrity. She calls against any further destabilization of Ukraine, whether from the inside or the outside," reads the statement.

Political demands, according to Ashton, should be addressed in a non-violent way through appropriate forums. Presidential elections next month need to provide a legitimate and inclusive platform for citizens to express their views about Ukraine's future.

Ashton also noted the vital importance that Ukraine's constitutional reform is comprehensive and completed without delay. In her opinion, the Ukrainian government needs to reach out to the population from east to west of Ukraine, and ensure that political processes as well as reforms reflect the regional diversity and respect human and civil rights.

The EU stands by the Ukrainian government in its efforts to stabilize the situation, reads the statement.

The document recalls that the EU Foreign Affairs Council will assess recent events in Ukraine on April 14.