Not long ago, the cadets at the military academy in east Ukraine's industrial hub of Donetsk swore allegiance to the Ukrainian flag.

Now, as fighting rumbles on between between pro-Russian insurgents and government forces, they are pledging an oath of loyalty to the rebels' self-proclaimed Donetsk People's Republic (DNR).

Russian President Vladimir Putin, who is fiercely protective of his private life, said Sunday that his two daughters -- who had reportedly lived abroad with their foreign partners -- now live in Moscow.

In a rare glimpse into the Russian ruler's notoriously secretive family life, Putin told the TASS news agency he tries to meet his daughters Maria, 29, nicknamed Masha, and Yekaterina, 28, known as Katya, every month.

Dutch experts on Sunday completed the recovery of wreckage from the crash site of downed Malaysia Airlines flight MH17 in eastern Ukraine and have sent it to a government-controlled city en route for the Netherlands

"(Transport of) the recovered wreckage from flight MH17 is under way towards Kharkiv," by train, the Dutch Safety Board (OVV) said in a statement.

Russian President Vladimir Putin is considering running for a fourth Kremlin term in 2018, which would see him stay in power until 2024, the TASS news agency reported Sunday.

"Yes, the possibility exists of my standing as a candidate again. Whether or not it will happen, I don't know yet," Putin said in an interview.

When Ukraine pulled out of its association agreement with the European Union a year ago, kicking off its revolution, it took Brussels by surprise.

Twelve months later the EU is still learning bitter lessons about geopolitics and Russian aggression, experts say.

Russia on Saturday accused the West of seeking regime change in Moscow, raising tensions over the conflict in Ukraine in the worst crisis in relations since the end of the Cold War.

Foreign Minister Sergei Lavrov spoke out against Western sanctions on Russia after U.S. Vice President Joe Biden hinted Friday at possible further measures over its "unacceptable" role in the former Soviet state.

Russia has 7,500 troops in the east of the country, where pro-Moscow separatists have been fighting government troops for months, Ukraine's defense minister said.

"Unfortunately, the stabilization of the situation in the east of Ukraine does not depend only on us," Stepan Poltorak said in a statement posted on the ministry's website on Saturday.

A Russian spy, jailed in Germany with her husband last year, has been freed early and allowed to return home, media reports said Friday, suggesting a possible prisoner swap.

The 48-year-old woman, known only by the pseudonym Heidrun Anschlag, was freed two days ago and returned to Russia while her 53-year-old husband, known as Andreas, remains in detention, the DPA news agency and Focus magazine reported.

Ukraine's new coalition government declared joining NATO a priority Friday in a move likely to provoke fresh Russian anger as thousands gathered in Kiev to mark the first anniversary of protests which unleashed a year of turmoil.

A crowd of several thousand gathered in Kiev's Independence Square, known as Maidan, late Friday to remember the more than 100 protestors who died in demonstrations that started on November 21 last year. 

U.S. Vice-President Joe Biden warned on a visit to Kiev Friday that Russia risked further isolation over its "unacceptable" aggression in Ukraine.

"It's simply unacceptable in the 21st century for countries to attempt to redraw borders by force... because they don't like a decision their neighbor has made," he said after meeting Ukrainian President Petro Poroshenko.