Ukrainian President Petro Poroshenko on Wednesday proposed constitutional changes designed to give broader powers to the regions, but failed to address the demands of pro-Russian fighters in the separatist east.

Poroshenko's new vision of the ex-Soviet state's basic law would trim presidential power over the provinces and extend to local towns and councils the right to oversee how their tax revenues are spent.

Ukraine announced on Tuesday the immediate suspension of all Russian gas purchases following a breakdown of EU-mediated price negotiations aimed at keeping supplies running for the next three to six months.

The state energy company Naftogaz said it would still continue transporting Russian gas supplies westward to its other European customers.

Russia's Prosecutor General is reviewing the legality of the independence of the three Baltic countries from the Soviet Union, a spokesman said Tuesday.

The move drew a furious reaction from Lithuania's President Dalia Grybauskaite, who said, "No one has the right to threaten" our independence.

Dutch prosecutors said Tuesday they have identified many "persons of interest" in their probe into the shooting down of flight MH17 over Ukraine, but no definite suspects.

"We have a large group of people that we're at this stage branding 'persons of interest' in whom we have an above average interest," Dutch chief prosecutor Fred Westerbeke told a press briefing in Rotterdam.

Russian investigators said on Tuesday that Kremlin critic Mikhail Khodorkovsky might have ordered the murder of a Siberian mayor, and that they would seek to question the former tycoon.

Investigators announced they were reviving a criminal probe into the 1998 murder amid efforts by Khodorkovsky, ex-owner of the former oil company Yukos, to challenge President Vladimir Putin's grip on power from his self-imposed exile in Switzerland.

Russia bid farewell Monday to former prime minister, foreign minister and master spy Yevgeny Primakov, with a state funeral for one of the last Soviet-era political titans who died last week aged 85.

Dignitaries led by President Vladimir Putin paid their last respects to the former prime minister, whose remains lay in state in the House of Unions in central Moscow flanked by an honor guard.

Russian President Vladimir Putin has pledged to support Syria's government "politically, economically and militarily," the war-torn country's Foreign Minister Walid Muallem said in Moscow on Monday.

"I received a promise from President Putin to support Syria politically, economically and militarily," Muallem said at a press conference with his Russian counterpart after meeting Putin.

A U.S. warship arrived Sunday in Georgia's Black Sea port of Batumi on a training mission, the U.S. embassy said, sending a message of support to the NATO aspirant amid the conflict in Ukraine.

The U.S. 6th Fleet's guided missile destroyer USS Laboon "will conduct routine combined training with the Georgian Coast Guard," the U.S. embassy in Tbilisi said.

A Russian lawmaker, who has strongly backed anti-gay legislation, said Facebook should be shut down in Russia over its support for the U.S. Supreme Court's decision to legalize same-sex marriage.

Lawmaker Vitaly Milonov said he would formally request Russia's telecoms oversight agency to shut down Facebook which has introduced a function allowing users to decorate their profiles with the rainbow flag of the gay rights movement.

Sweden is stepping up its military capabilities and exercises with NATO amid concerns over Russia's military resurgence, Defense Minister Peter Hultqvist said on Friday.

"It's a general fact that Russia is carrying out bigger, more complex, and in some cases more provocative and defiant, exercises. We are following that development and are now strengthening our military capability and our international cooperation," Hultqvist told paper of reference Dagens Nyheter.