Finland has announced its desire to join NATO "without delay," prompting a sharp warning from the Kremlin as Moscow's ongoing war in Ukraine, which President Vladimir Putin has said he launched to prevent the alliance's expansion, reshapes Europe's security architecture.
Russia also appeared to lose ground on the battlefield on May 12, with Ukraine's military claiming it had pushed back Russian forces in a counterattack in the east that could mark the beginning of a shift in the momentum of the war.
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"NATO membership would strengthen Finland's security. As a member of NATO, Finland would strengthen the entire defense alliance. Finland must apply for NATO membership without delay," Finnish President Sauli Niinisto and Prime Minister Sanna Marin said in a joint statement.
Finland, which shares a 1,340-kilometer border and a turbulent relationship with Russia, has stepped up its cooperation with NATO since Russia seized Crimea in 2014.
Putin cited in part what he called the threat from NATO, which expanded eastwards after the Cold War, as a reason for launching his invasion of Ukraine.
The announcement in Helsinki prompted Russia to warn that it would have to take "military-technical" steps in response.
"The expansion of NATO and the approach of the alliance to our borders does not make the world and our continent more stable and secure," Kremlin spokesman Dmitry Peskov told reporters.
Asked whether Finland's membership would be a threat, Peskov answered: "definitely."
"Everything will depend on how this process takes place, how far the military infrastructure will move towards our borders," he said.
In Helsinki, Niisto and Marin said in their statement that a special committee will announce a formal Finnish decision on a membership bid on May 15 as another Nordic country, the traditionally neutral Sweden, is also expected to announce its intention to join NATO in the coming days.
NATO officials have indicated that the accession protocols for Finland and Sweden could be signed when the alliance holds a summit in Madrid on June 28-29 if the formal applications landed on NATO Secretary-General Jens Stoltenberg’s desk by the end of this month.
Finland fought two wars with the Soviet Union between 1939 and 1944, repelling an attempted invasion but losing 10 percent of its territory in the subsequent peace agreement.
Finland maintained its neutrality in the postwar period, acting at times as an intermediary between Moscow and the West.
The diplomatic moves made abroad came as Ukraine's General Staff said its forces had recaptured Pytomnyk, a village on the main highway north of Kharkiv, a city located just 40 kilometers from the border.
In its daily intelligence bulletin, Britain's Ministry of Defense noted that the withdrawal of Russian forces from the Kharkiv area was "a tacit recognition of Russia's inability to capture key Ukrainian cities where they expected limited resistance from the population."
Russian forces continue to pound a steel plant in the southern port city of Mariupol that is the last bastion of Ukrainian resistance, its defenders said.
Ukraine offered to release Russian prisoners of war in exchange for the safe evacuation of badly wounded fighters trapped inside the Azovstal steel plant.
Ukrainian Deputy Prime Minister Iryna Vereshchuk said that negotiations were under way to release the wounded. She said there were different options, but “none of them is ideal.”
Russia hasn't confirmed any talks on the subject.
Officials said in recent weeks that about 100,000 residents could still be trapped in Mariupol, which had a prewar population of over 400,000.
Russian and Ukrainian authorities have agreed to cease-fires to evacuate residents, but those efforts have subsequently failed most of the time.
Russia, meanwhile, said on May 12 that its forces hit two ammunition depots in the Chernihiv region of Ukraine. The Defense Ministry said Russia had destroyed a Ukrainian S-300 air defense missile system in the Kharkiv region and a radar station near Odesa.
Earlier on May 12, leaders of the European Union warned that Russia posed the "most direct threat" to world order and called Moscow's invasion of Ukraine "barbaric" as heavy fighting in the east and south of the country continued.
European Commission President Ursula von der Leyen, who is in Japan together with European Council President Charles Michel, held talks on May 12 with Japanese Prime Minister Fumio Kishida that have touched on Moscow's invasion.
Russia "is today the most direct threat to the world order with the barbaric war against Ukraine, and its worrying pact with China," von der Leyen said after meeting Kishida.
As fighting raged in southern and eastern Ukraine, Kyiv said it will not reopen the suspended Sokhranovka gas transit route from Russia to European customers until it obtains control over its gas transit system.
On May 11, Russian gas flows to Europe via Ukraine fell by a quarter after Kyiv announced it would stop Russian shipments through a hub in the east, blaming interference by Russian forces in the region.
It was the first time exports have been disrupted since Moscow launched its unprovoked invasion of Ukraine, but the immediate effect is likely to be limited because Russia can divert the gas to another pipeline and because Europe relies on a variety of suppliers.