BRUSSELS -- NATO Secretary-General Jens Stoltenberg says there has been a "serious military buildup" both in conflict-torn eastern Ukraine and on the Russian side of the border, and he has urged Moscow to pull back its forces.
Stoltenberg told reporters in Brussels that information from NATO and other sources including the OSCE pointed to "a military buildup...inside Ukraine, but we also see a military buildup on the Russian side of the border."
"And we speak about troops, we speak about equipment, and we speak also about artillery and very modern air-defense systems so this is a serious military build-up," he said upon arrival for a meeting with European Union defense ministers.
Stoltenberg urged Moscow to adhere to its commitment to a cease-fire and peace plan agreed in Minsk on September 5, saying that Russia could be "part of a peaceful negotiated solution or...continue on a path of isolation."
"We see that Russia is still destabilizing Ukraine, we see the movement of troops, of equipment, of tanks, of artillery and also advanced air defense systems and this is in violation of the cease-fire agreement," he said. "And we call on Russia to pull back its forces from eastern Ukraine and to respect the Minsk agreement."
The remarks came after Western leaders, at a G20 summit in Brisbane, Australia, on November 15-16, piled pressure on Russian President Vladimir Putin to halt what Kyiv and NATO say is Moscow's direct military support for pro-Russian rebels who control large parts of eastern Ukraine's Donetsk and Luhansk provinces.
Putin denies the accusations of a Russian military role despite what Western governments say is mounting evidence, from recent sightings of unmarked convoys by OSCE observers to funerals of Russian soldiers in their home regions.
In an interview with Germany's ARD television broadcast on November 18, Putin said separatists in eastern Ukraine faced the threat of a new government offensive and strongly suggested that Russia would help them if necessary -- or was already doing so.
"You want the Ukrainian central authorities to annihilate everyone there, all of their political foes and opponents?" Putin said in the interview. "Is that what you want? We certainly don't. And we won't let it happen."
Ukrainian Prime Minister Arseniy Yatsenyuk, meeting with German Foreign Minister Frank-Walter Steinmeier in Kyiv on November 18, said that "basic points" of the Minsk agreement "have not been fulfilled."
"Russia must fulfil what it signed and what it promised to the whole world," he said.
Steinmeier, who was expected to travel to Moscow later in the day, said, "I will leave this afternoon to see whether the talks in Brisbane created an atmosphere which would allow for work on more concrete implementations of the Minsk agreement."
The conflict in eastern Ukraine has killed more than 4,100 people since April, raised concerns about Moscow's intentions elsewhere, and brought Moscow's relations with the West to post-Cold War lows.
Ties had already been badly damaged by Russia's annexation of Crimea in March, which followed the flight of a Russian-backed president from Ukraine after months of protests over his November decision to spurn a landmark political and economic pact with the European Union and turn to Moscow instead.
A Ukrainian military spokesman said on November 18 that five Ukrainian troops had been killed in the previous 24 hours, and reported shelling of government positions in several locations including the Donetsk airport.
Also on November 18, Russian Foreign Minister Sergei Lavrov is accusing Kyiv of trying to "strangle" separatist-held territories in eastern Ukraine by cutting off payments and ordering the closure of state institutions in the rebel-controlled areas.
Lavrov repeated Moscow's calls for the Ukrainian government to hold talks with the pro-Russian separatists but said that instead, "Kyiv has set a course for the socioeconomic strangulation of southeastern Ukraine and is threatening to revive [efforts to] resolve the conflict by force."
Kyiv's moves are a response to the military buildup and to elections held by the separatists in the self-proclaimed "People's Republics" of Donetsk and Luhansk on November 2, which Ukraine and the West condemned as an illegal violation of a September 5 peace plan.
With reporting by RFE/RL's Rikard Jozwiak, Reuters, TASS, Interfax, and AFP