Australian Prime Minister Tony Abbott on Thursday warned Vladimir Putin he will not be able to avoid a "conversation" over the loss of Australian lives in the downing of Flight MH17 over Ukraine.

Last month Abbott vowed to "shirtfront" the Russian president at the G20 summit in Brisbane next week.

Syria has asked Russia to speed up delivery of S-300 anti-aircraft missiles, concerned about a possible U.S. attack, Syrian Foreign Minister Walid Muallem said in an interview published Thursday.

Speaking to Lebanon's Al-Akhbar newspaper, Muallem said Washington had pledged that U.S.-led air strikes against the Islamic State group would not hit the Syrian army.

Moscow slammed Kiev Thursday for violating the ceasefire in eastern Ukraine, accusing it of intensifying its military offensive against rebels.

"It is obvious today that these agreements have been crudely violated by the Ukrainian side," the Russian foreign ministry said.

As a deadline for the controversial delivery of a warship to Russia nears, France faces a grueling dilemma: ditch the deal, lose billions and antagonize Moscow -- or go ahead and attract NATO's wrath.

Until the deadly crisis in Ukraine erupted this year, the 1.2 billion-euro ($1.5-billion) contract to build and sell two mammoth Mistral-class assault ships to the Russian navy had been firmly on track.

Ukraine on Thursday announced passport controls around areas held by pro-Russian separatists in the latest step toward what resembles the breakup of the ex-Soviet republic, as heavy artillery fire erupted in Donetsk.

Ukraine's border guards service said anyone crossing in or out of rebel areas will have to present a passport. Foreigners will "be sent to filtration points to determine the purpose of their visit" and will have "to show a passport or the required visa," a statement said.

Russia has confirmed it will not attend the 2016 Nuclear Security Summit, a gathering championed by President Barack Obama, accusing Washington of seeking to play first fiddle on matters of nuclear safety.

In another sign of the growing chill between the former Cold War rivals, Moscow claimed the organizers wanted to accord special rights to the United States along with South Korea and the Netherlands, which hosted previous summits, while discriminating other participants.

U.S. authorities are investigating a member of Russian President Vladimir Putin's inner circle for money-laundering, The Wall Street Journal reported Wednesday.

In a politically thorny tightening of screws on Putin's billionaire allies, the Justice Department and New York state prosecutors are looking into whether Gennady Timchenko transferred funds linked to allegedly corrupt deals in Russia through the U.S. financial system, the Journal reported citing a number of unnamed people familiar with the case.

U.S. Secretary of State John Kerry on Wednesday warned Russia that sanctions pressure could be intensified over the Ukraine crisis but urged Kiev not to get drawn into "tit-for-tat" measures.

Speaking to reporters in Paris after holding talks with French Foreign Minister Laurent Fabius, Kerry said "the choice is Russia's" as to whether to implement the Minsk agreement that was supposed to bring peace to Ukraine's restive east.

The Portuguese Navy escorted a Russian oceanographic ship out of its waters Wednesday in response to the latest in a series of territorial incursions by a Russian vessel or plane.

Portugal identified the ship in the section of sea it has exclusive resource rights over and then guided the vessel back into international waters, Portugal's Defense Minister Jose Pedro Aguiar-Branco told Portuguese press agency LUSA.

For a second year in a row, Russian President Vladimir Putin has beaten Barack Obama to the title of world's most powerful leader as ranked by Forbes.

In a year in which Russia annexed Crimea, stoked a conflict in Ukraine and clinched a multi-billion-dollar gas pipeline deal with China that Forbes called the world's largest construction project, Putin remained on top.