Russia’s foreign minister on Tuesday warned anew Ukraine that it must demilitarize, threatening further military action and falsely accusing Kyiv and the West of fueling the war that started with Moscow’s invasion.

Sergey Lavrov said Ukraine must remove any military threat to Russia — otherwise “the Russian army (will) solve the issue.” His comments also reflected persistent unfounded claims by the Kremlin that Ukraine and its Western allies were responsible for the 10-month war, which has killed tens of thousands of people and displaced millions.

Russia launched the war on Feb. 24, alleging a threat to its security and a plot to bring NATO to its doorstep. Lavrov reiterated on Tuesday that the West was feeding the war in Ukraine to weaken Russia, and said that it depends on Kyiv and Washington how long the conflict will last.

“As for the duration of the conflict, the ball is on the side of the (Kyiv) regime and Washington that stands behind its back,” Lavrov told the state Tass news agency. “They may stop senseless resistance at any moment.”

In an apparent reaction, Ukrainian presidential adviser Mykhailo Podolyak tweeted that “Russia needs to face the reality.”

“Neither total mobilization, nor panicky search for ammo, nor secret contracts with Iran, nor Lavrov’s threats will help,” he said. “Ukraine will demilitarize the RF (Russian Federation) to the end, oust the invaders from all occupied territories. Wait for the finale silently…”

A day earlier, Ukraine’s Foreign Minister Dmytro Kuleba told the Associated Press in an interview that his government wants a summit to end the war but that he doesn’t anticipate Russia taking part.

Kuleba said Ukraine wants a “peace” summit within two months with U.N. Secretary-General António Guterres acting as mediator. But he also said that Russia must face a war crimes tribunal before before his country directly talks with Moscow.

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Both statements illustrate how complex and difficult any attempts to end the war could be. Ukraine has said in the past that it wouldn’t negotiate with Russia before the full withdrawal of its troops, while Moscow insists its military gains and the 2014 annexation of the Crimean Peninsula cannot be ignored.

Testifying to the hardships of war, families of Ukrainian prisoners of war believed held by Russia on Tuesday said the Christmas holiday season is particularly painful and appealed for more to be done to bring their loves ones back home.

Neither Ukraine nor Russia have revealed the exact numbers of POWs they hold, while hundreds have been released as part of prisoner exchanges. Iryna Latysh’s husband Yevhen was captured exactly 300 days ago, in the early days of the war, and she says Christmas isn’t the same without him.

“We were decorating the Christmas tree together this time last year,” she sobbed. “We put the star together, the decorations.”

U.N. human rights investigators have warned that Ukrainian POWs appear to be facing “systematic” mistreatment — including torture — both when they are captured and when they are transferred into areas controlled by Russian forces or Russia itself.

Meanwhile, fierce fighting continued on Tuesday in the Russia-claimed Donetsk and Luhansk regions that recently have been the scene of the most intense clashes.

Ukraine’s Deputy Defense Minister Hanna Maliar said that Russian forces are trying to encircle the city of Bakhmut in the Donetsk region, but without success. Heavy battles are also underway around the city of Kreminna in the Luhansk region, Luhansk governor Serhiy Haidai said.

In the partially occupied southern Kherson region, Russian forces shelled Ukrainian-held areas 40 times on Monday, wounding one person, Ukrainian authorities said. The city of Kherson itself — which Ukraine retook last month in a major win — was targeted 11 times, said regional administrator Yaroslav Yanushevich.

Since its initial advances at the start of the war 10 months ago, Russia has made few major gains, often pummeling Ukraine’s infrastructure instead and leaving millions without electricity, heating and hot water amid winter conditions.

Lavrov didn’t specify how the Russian army will achieve its goals of demilitarizing and “denazifying” Ukraine — which was Russia’s stated goal when the invasion started in February. The reference to “denazification” comes from Russia’s allegations that the Ukrainian government is heavily influenced by radical nationalist and neo-Nazi groups. The claim is derided by Ukraine and the West.

Lavrov warned further Western support for Ukraine could lead to direct confrontation.

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“We keep warning our adversaries in the West about the dangers of their course to escalate the Ukrainian crisis,” he said, adding that “the risk that the situation could spin out of control remains high.”

“The strategic goal of the U.S. and its NATO allies is to win a victory over Russia on the battlefield to significantly weaken or even destroy our country,” he said.

On Tuesday, Russian President Vladimir Putin signed a decree banning oil exports to countries that support a $60-per-barrel price cap that was declared by the European Union and Group of Seven countries in a bid to reduce Moscow’s revenue during wartime. The ban takes effect in February and will run through July.

The price cap is higher than what Russian oil has sold for in recent weeks, so the potential effects of Putin’s ban are uncertain.