Ukraine's president is to chair a crisis meeting of his security chiefs, following elections in rebel-held areas which Kiev describes as a "farce".

Western leaders have criticised Russia for its "destabilising" influence on the crisis in Ukraine, at the start of a Nato summit in Wales.

 US President Barack Obama has arrived in Estonia for talks on Russia and the Ukraine crisis with Baltic leaders.

 Ukrainian President Petro Poroshenko says a "roadmap" will be prepared to end fighting between troops and pro-Russian separatists in the east.

 Ukrainian President Petro Poroshenko is due to take part in talks with his Russian counterpart, Vladimir Putin, at a summit in Minsk, capital of Belarus.

 The southern city of Odessa was drawn dramatically into the Ukrainian crisis on 2 May when more than 40 people were killed in a burning building following street fighting.

 U.S. space agency NASA said Wednesday that it has suspended the majority of its engagements with Russia due to the Ukraine crisis.

 British Prime Minister David Cameron and Russian President Vladimir Putin on Sunday agreed in a phone call that they both want to find a "diplomatic solution" to the situation in Ukraine, a Downing Street spokesperson said Sunday.

 EU leaders are to begin an emergency summit to decide how strongly they should respond to Russia's troop deployment in Ukraine's Crimea region.

 Ukraine's opposition MPs are expected to push for laws that will reduce the power of the president, as parliament begins a new term on Tuesday.