A Dutch team recovered more body parts at the MH17 crash site in war-torn Ukraine, where 298 were killed when a Malaysia Airlines jetliner crashed in July, officials said Monday.

"They recovered a small amount of human remains of the victims," Dutch defense ministry spokeswoman Marloes Visser said.

Pro-Russian separatists vowed Monday to mobilize up to 100,000 fighters for their latest east Ukraine offensive as the United States mulled sending weapons to Kiev's outgunned forces after the latest truce bid collapsed.

The pledge to dramatically escalate a nine-month conflict that has already left at least 5,100 people dead came as the rebels battled to encircle the beleaguered transport hub of Debaltseve.

NATO's military commander and Obama administration officials appear to be moving toward supporting sending defensive weapons to Kiev's forces fighting pro-Russian separatists in eastern Ukraine, The New York Times reported Sunday.

Though President Barack Obama has not yet decided whether to send "lethal assistance," his administration is reviewing the issue after a surge in fighting between Kiev and Kremlin-backed rebels, the Times reported.

Hungary's maverick Prime Minister Viktor Orban has spent the past year straddling the divide between Russia and his European Union counterparts on the crisis in Ukraine.

But he may soon be forced to pick sides.

Two Russian television journalists working for the pro-Kremlin Life News channel have been arrested in Ukraine and will be expelled, Ukraine's security service (SBU) spokesman Markiyan Lubkivskiy said on Friday.

"The SBU arrested two Russian citizens working as journalists for Life News. Their residency permits have been canceled and they will be expelled from our country and barred from returning to Ukraine for three years," Lubkivskiy wrote on his Facebook page.

Truce talks between Ukraine's government and pro-Russian insurgents appeared to collapse Friday after 24 people, mostly civilians, were reported killed in heavy weapons fire in eastern Ukraine, prompting new European criticism of Russia.

Plans for the talks in the Belarussian capital Minsk were announced on Thursday, raising hopes of dialogue amid the collapse of a September truce in a war that has killed at least 5,100 people, according to the United Nations.

North Korea's leader Kim Jong-Un looks set to take an initial, tentative step onto the global stage with a visit in May to Russia -- his first trip abroad since coming to power three years ago.

Kim may not have the physique or bearing of a shy debutante, but Moscow will be his diplomatic "coming out" and minutely scrutinised, especially with other world leaders, including China's Xi Jinping, expected to be there.

The United States warned Russia on Thursday that it is mulling fresh sanctions over the fighting in Ukraine and welcomed an EU move to broaden existing measures imposed on Moscow.

State Department spokeswoman Jen Psaki said the agreement by EU foreign ministers to expand existing European sanctions "is just a further sign that the actions of the last several days and weeks are absolutely unacceptable and that there will be new consequences put in place."

Britain said it had summoned the Russian ambassador Thursday after Russian military planes were found flying close to British airspace.

The move comes after a string of similar incidents and amid tense relations between Moscow and the West over the conflict in Ukraine and the killing in London of former Russian spy Alexander Litvinenko.

Deputy NATO head Alexander Vershbow on Thursday praised Georgia's democratic reforms and reiterated the alliance's commitment to the ex-Soviet country's eventual membership in the 28-nation bloc.

"We truly commend the reforms aimed to strengthen your defense, rule of law, and governance," Vershbow told reporters in the Georgian capital Tbilisi after a meeting with the country's Prime Minister Irakli Garibashvili.