World leaders have condemned Russia’s partial mobilisation to fight in Ukraine, saying it is another “terrible and wrong step” which will not help it win the war.
Russian President Vladimir Putin announced the plan on Wednesday, confirming reservists are being conscripted to fight in Ukraine.
About 300,000 troops will be called up, prompting flights out of the country to almost sell out.
In a rare televised address to the nation, in which he referred to nuclear weapons, Mr Putin warned Russia would use “all the means” available in Ukraine. He stressed the threat was “not a bluff”.
Nato Secretary General Jens Stoltenberg accused Mr Putin on Wednesday of “dangerous” rhetoric on Wednesday, following his address.
“This is dangerous and reckless nuclear rhetoric,” Mr Stoltenberg said, on the sidelines of the United Nations General Assembly in New York.
“It's not new as he has done it many times before. He knows very well that a nuclear war should never be fought and cannot be won, and it will have unprecedented consequences for Russia.”
Russian forces have been on the back foot in Ukraine since the start of September, when Kyiv launched a lightning offensive. This has led to Ukraine retaking about 6,000 square kilometres of territory.
Recent Ukrainian gains include almost all of Kharkiv province, but Russia still has control over about a fifth of the country.
“When the territorial integrity of our country is threatened, we will certainly use all the means at our disposal to protect Russia and our people,” Mr Putin said in the delayed address, which was originally scheduled to be broadcast on Tuesday night.
The move comes a day after four Russian-controlled regions in eastern and southern Ukraine announced plans to hold votes on becoming integral parts of Russia. These would potentially pave the way for Russia to annex an area of the country the size of Hungary.
Ukrainian President Volodymyr Zelenskyy said he does not believe Russia will actually use nuclear weapons.
“I don't believe that he will use these [nuclear] weapons,” Mr Zelenskyy told the TV station of Germany's Bild newspaper. “I don't believe that the world will allow him to use these weapons.”
Speaking on BBC Radio 4's Today programme, political scientist Sergei Markov said the use of nuclear weapons in Ukraine “could kill a lot of people in the western countries”.
But he said Russia has “no reason” to resort to them against Ukraine.
“Ukrainians are our brothers but Ukrainians are occupied by western countries.
“It is western countries who are fighting against [the] Russian army using Ukrainian soldiers as their slaves.”
A member of Mr Putin’s United Russia party in parliament who is also a state television presenter said Russia will not use nuclear weapons first.
“We are not going to attack western countries first,” Evgeny Popov said on BBC Radio 4’s World At One programme.
“We are not going to do some nuclear massacre in the world. “It’s not our policy. It’s not our practice. We are peaceful people in Russia, but we can respond if you would attack us.”
The UK's Defence Secretary Ben Wallace said the part mobilisation and illegal annexation of areas of Ukraine were an admission the invasion was failing.
“He and his defence minister have sent tens of thousands of their own citizens to their deaths, ill equipped and badly led,” he said.
“No amount of threats and propaganda can hide the fact that Ukraine is winning this war, the international community are united and Russia is becoming a global pariah.”
German's Economy Minister Robert Habeck said Mr Putin's speech was “another terrible and wrong step”.
“We will of course assess politically and discuss how to respond to it,” he said.
“In any case, for me and the German government it’s clear that we will continue to fully support Ukraine during this difficult time.”
The president of the EU, Charles Michel, also reiterated the bloc’s support for Ukraine.
“In this war, there is only one aggressor, Russia, and one aggressed country, Ukraine,” he tweeted.
“EU's support to Ukraine will remain steadfast.”
The mayor of the Ukrainian capital Kyiv, Vitali Klitschko, said the mobilisation and threats will not help Mr Putin conquer Ukraine.
“The tyrant finally launched the processes that will bury him in his country.
“And the civilised world must finally understand that evil must be eradicated from the roots, and not talk about some illusory 'peace negotiations'.”
Latvia, which borders Russia, said it would not offer Russians fleeing the mobilisation a safe haven.
The country’s foreign minister, Edgars Rinkevics, tweeted: “Latvia will not issue humanitarian or other types of visas to those Russian citizens who avoid mobilisation, nor will it change the border crossing restrictions for Russian citizens with Schengen visas introduced since September 19.”
In another tweet, Mr Rinkevics said the world must not give into Mr Putin’s “blackmail”.
“We must not give in to his blackmail and support Ukraine as much as we can. #Russia is as dangerous to Europe and the world’s peace today as Nazi Germany was in the last century #StandWithUkraine.”
He said the level of military threat to Latvia was still low.
Czech Republic Prime Minister Petr Fiala called the partial mobilisation “an attempt to further escalate the war Russia launched against Ukraine” and “further proof that Russia is the sole aggressor”.
His country has supplied the Ukrainian armed forces with heavy weapons, including tanks, armoured vehicles, helicopters and artillery systems.
Jailed opposition leader Alexey Navalny accused the president of expanding the war to maintain his grip on power.
“Putin is tormenting a neighbouring country, killing people there, and now he is throwing a huge number of Russian citizens into the meat grinder of war,”
He said in a video posted by his organisation: “It was a crime, and now it has become a crime of a much larger scale.”
Direct flights to cities in the nearby ex-Soviet countries of Armenia, Georgia, Azerbaijan and Kazakhstan were all sold out on Wednesday, the Aviasales website popular in Russia showed.
Meanwhile, Turkish Airlines said on its website that flights to Istanbul, which has become an important travel hub to and from Russia, were fully booked until Saturday.
The phrase “how to leave Russia” surged in Google searches on Tuesday before Mr Putin's much-anticipated speech, pointed out by the Mozhem Obyasnit Telegram channel.
