New European Commission chief Jean-Claude Juncker said Wednesday he would visit Kiev on his first trip outside the European Union, as the peace plan in Ukraine hung by a thread.

"I will be going to the Ukraine, I don't yet know when," Juncker told a press conference. "I promised the Ukrainian president (Petro Poroshenko) my first bilateral outside the EU will be in Kiev."

The ceasefire in Ukraine hung by a thread Wednesday after President Petro Poroshenko accused pro-Russian rebels of endangering the peace process and ordered troop reinforcements to eastern cities.

In another sign of how far apart the two sides are drifting, Prime Minister Arseniy Yatsenyuk announced he was cutting the rebel-held Donetsk and Lugansk regions off from central government subsidies, so as not to finance "terrorists."

The leaders of Malaysia and the Netherlands vowed on Wednesday to keep pressing for access to the crash site of Malaysia Airlines flight MH17 and to bring to justice those responsible for downing the plane in Ukraine.

Prime Minister Najib Razak met with his visiting counterpart Mark Rutte in Malaysia to discuss the Dutch-led investigation into the July 17 disaster, which killed 193 citizens of the Netherlands.

Tens of thousands of supporters of President Vladimir Putin and a smaller group of ultra-nationalists marched through Moscow on Tuesday to mark Russia's Unity Day.

The huge, highly organized rally of Putin backers through the center of the capital showcased the Kremlin's patriotic agenda at a time of growing international tension over the war in neighboring Ukraine.

NATO member Poland said Tuesday it will acquire combat drones as part of a multi-billion-euro revamp of its armed forces amid heightened tensions with Russia over its role in the Ukraine crisis.

"We will use these drones to defend our territory," Deputy Defense Minister Czeslaw Mroczek told AFP.

Ukraine is rearming and deploying new units to the east of the country to counter any attempt by pro-Russian rebels to take over more territory, President Petro Poroshenko said Tuesday.

At a crisis meeting of security chiefs in the capital Kiev, Poroshenko said that he had not given up on a deal brokered in September to end the seven-month conflict, in which more than 4,000 people have died.

Elections organized and won by separatists in eastern Ukraine over the weekend were "unfortunate and counterproductive," U.N. chief Ban Ki-moon said Tuesday.

Russia has opposed a U.N. Security Council move to criticize rebel elections held in eastern Ukraine, the Ukrainian ambassador said Monday.

A statement from the 15-member council was discussed on Friday and again at the weekend, but Russia fiercely opposed it.

Russia's recent military flights into European airspace are meant to demonstrate to the West that the country is a "great power," NATO's supreme allied commander said on Monday.

Although there has been an increase in Russian air activity over Europe during the past year, last week marked the first time Moscow had sent in larger formations of warplanes, General Philip Breedlove told reporters.

Europe on Monday warned Russia to respect Ukraine's unity as Moscow piled pressure on Kiev by recognizing controversial rebel polls aimed at giving legitimacy to a bloody pro-Kremlin insurgency.

German Foreign Minister Frank-Walter Steinmeier said the elections went "against the letter and spirit" of an internationally brokered truce deal in September that was meant to halt the war in eastern Ukraine.