Amid growing concern over a Russian military buildup near the Ukrainian border, NATO allies have warned Russia that it would pay a heavy price for any new military aggression against its neighbor, while Moscow cautioned the Western military alliance against crossing its "red lines."
The Western warning came as NATO foreign ministers in Riga, the capital of Baltic alliance member Latvia, held a meeting focused on the threat posed by Russia.
Ukraine says Russia has kept tens of thousands of troops and heavy equipment near their common border following massive war games in western Russia earlier this year, raising fears of a possible invasion.
Russia, which seized Crimea from Ukraine in 2014 and backs separatists fighting against Kyiv in an ongoing conflict that has killed more than 13,200 people over the past seven years, denies it is plotting an attack and blames Ukraine and its Western backers for fueling tensions.
NATO Secretary-General Jens Stoltenberg told reporters in Riga that "there will be a high price to pay for Russia if they once again use force" against Ukraine, and noted that the West had already imposed economic, financial, and political sanctions against Moscow.
"You can discuss whether the likelihood for an incursion is 20 percent or 80, it doesn't matter. We need to be prepared for the worst," Stoltenberg said. "They’ve done it before."
U.S. Secretary of State Antony Blinken told journalists after the talks in Riga that any renewed aggression in Ukraine would trigger "serious consequences."
"We are very concerned about the movements we've seen along Ukraine's border. We know that Russia often combines those efforts with internal efforts to destabilize a country. That's part of the playbook, and we're looking at it very closely," he said.
In Washington, White House spokeswoman Jen Psaki said on November 30 that the White House remained "deeply concerned" about heightened rhetoric around the reported Russian military buildup on Ukraine's border, which follows a similar surge in the spring, when Moscow gathered around 100,000 troops on Ukraine's borders but later announced a drawdown.
Additional support for Ukraine's military and the potential of strengthening NATO forces positioned along the alliance's eastern border are topics expected to be on the agenda at the two-day meeting in the Latvian capital.
The allies are looking to show the Kremlin it will face severe costs if it threatens Ukraine, while stopping short of provoking Moscow into further aggression.
In Moscow, President Vladimir Putin warned that Russia would be forced to act if its "red lines" were crossed by NATO member states, saying Moscow would view the deployment of certain offensive missile capabilities on Ukrainian soil as a trigger.
Putin, addressing an investment forum, reiterated Moscow's concerns over Western military drills near Russia's borders, singling out recent U.S.-led exercises in the Black Sea.
The ministers of the 30-country defense bloc will "together send an unmistakable message to the Russian government: NATO's support for Ukraine is unbroken and its independence, territorial integrity, and sovereignty are not up for discussion," German Foreign Minister Heiko said.
British Foreign Secretary Liz Truss said that any suggestion that NATO was provoking Russia was "clearly false," adding that "any action by Russia to undermine the freedom and democracy that our partners enjoy would be a strategic mistake."
Ukrainian Foreign Minister Dmytro Kuleba told foreign media in Kyiv on November 29 that Russia had amassed 115,000 troops and heavy weapons near his country's border, on the occupied territory of Crimea, and in parts of the two eastern Luhansk and Donetsk regions of Ukraine occupied by Kremlin-backed separatists.
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The gathering in Riga also had on the agenda a weeks-long migrant crisis on the alliance’s eastern flank.
The European Union has accused Moscow ally Belarus of funneling thousands of mainly Middle Eastern migrants to its borders with EU and NATO members Poland, Lithuania, and Latvia in retribution for sanctions imposed by the bloc over a sweeping crackdown since last year's disputed presidential election.
Belarusian strongman Alyaksandr Lukashenka rejects the accusation.
NATO has expressed "solidarity" with its eastern members, and Stoltenberg and EU Commission President Ursula von der Leyen on November 28 pledged to step up cooperation against the migrant challenge. Von der Leyen said the EU would increase border management funding for the three countries.
The tensions have eased since Iraq began flying some migrants back to the country, but Warsaw and Vilnius insist the crisis is far from over.
The foreign ministers will also discuss NATO's operations in Afghanistan, reflecting on lessons learned, and NATO's master strategy document, known as the Strategic Concept, which will guide the alliance as it addresses current and emerging challenges, the U.S. State Department statement said.
The new Strategic Concept is being prepared for adoption at the NATO summit in Madrid, Spain, in June 2022.