Russian Foreign Minister Sergei Lavrov is to meet his German counterpart in Moscow next week for talks on the escalating conflict in Ukraine, Moscow said Thursday.

"On November 18 we are expecting a visit from German Foreign Minister Frank-Walter Steinmeier," Russian foreign ministry spokesman Alexander Lukashevich said at a televised briefing.

International pressure on Russia was mounting Thursday over claims it is sending fresh military hardware into eastern Ukraine which could fuel a return to all-out conflict.

After NATO accused Russia of deploying tanks, troops and military hardware to the region, Ukraine said four of its soldiers had been killed in the past 24 hours and 18 wounded.

Australia said Thursday it is tracking four Russian navy ships off its north coast, a move Prime Minister Tony Abbott said was a sign of Moscow's military assertiveness with relations strained after the downing of Flight MH17 in Ukraine.

The appearance of the fleet coincides with Vladimir Putin's arrival at the G20 summit in Brisbane this weekend and follows a highly anticipated exchange between the Russian leader and Australian premier Tony Abbott in Beijing.

Russian Foreign Minister Sergei Lavrov and his U.S. counterpart John Kerry called on Wednesday for an agreement on a nuclear deal with Iran to be reached as soon as possible.

"The need to reach as soon as possible a comprehensive agreement which would allow to fully normalize the situation around the Iranian nuclear program has been acknowledged," the Russian foreign ministry said following a call between Lavrov and Kerry.

From Cheshire Cat-like grins to gloom invoking Eeyore the donkey, the diplomatic menagerie surrounding an annual Asia-Pacific summit meeting left observers with a "through the looking glass" sense of the absurd.

A week of summitry in Beijing offered insights into the diplomatic relationships -- strained as well as warm -- and the shifting dynamics of power between globetrotting leaders.

NATO on Wednesday accused Russia of sending fresh columns of tanks, troops and military hardware into Ukraine as Kiev said it was preparing for a return to combat in the war-torn east.

Ukraine's warning will fuel fears of a return to all-out conflict despite a two-month-old ceasefire deal which has halted fighting along much of the frontline but not stopped shelling at strategic flashpoints.

Turkey could scrap a controversial plan to buy missile defense systems from China that alarmed the United States and its Western allies, Turkish and European sources said Wednesday.

Key NATO member Turkey said in September last year it was entering negotiations with the China Precision Machinery Export-Import Corporation (CPMIEC) to acquire its first long-range anti-missile systems.

Russia on Tuesday refused to endorse a U.N. resolution on Bosnia that Moscow said would push the Balkan country towards NATO and the European Union -- a scenario that led to the conflict in Ukraine. 

The U.N. Security Council adopted the resolution backing the EU military force in Bosnia despite Russia's absention, but the outcome reflected East-West tensions over Ukraine.

A Russian court in Chechnya's capital of Grozny has sentenced a man to two years for fighting in Syria against Bashar al-Assad's regime, a report said Tuesday.

The man, Said Mazhayev, fought in the rebel Free Syrian Army from November 2013 to January 2014 and was charged with participating in a foreign armed group when he returned home, according to case details on the prosecution's webpage.

Finnish Prime Minister Alexander Stubb warned Tuesday that the conflict in the Ukraine was bringing the world to the "brink of a Cold War" but that trade sanctions were the only credible weapon against Russia.

"Russia's foreign policy doctrine has Cold War elements," he told public broadcaster YLE.