MOSCOW (Reuters) - President Vladimir Putin's spy chief warned the West on Wednesday that it risked disastrous consequences if the United States and its European allies stoke a direct military confrontation with Russia over Ukraine.
Moscow has criticised a decision by Washington to let Ukraine use U.S. missiles to strike into Russia, and on Tuesday Putin lowered the threshold for a nuclear strike in response to a broader range of conventional attacks.
The rising tensions prompted a flight to safety in some financial markets amid concern that there could be a global confrontation to echo the 1962 Cuban Missile Crisis, when the Cold War superpowers came closest to intentional nuclear war.
Sergei Naryshkin, the head of Russia's Foreign Intelligence Service (SVR), said Russia would punish any NATO states that help Ukraine strike deep into Russia with long-range Western weapons.
"Attempts by individual NATO allies to participate in providing for possible long-range strikes with Western weapons deep into Russian territory will not go unpunished," Naryshkin told the magazine National Defence.
Russia said Ukraine fired U.S. ATACMS missiles into Russia early on Tuesday morning and suggested that the United States must have helped the strikes with satellite data, targeting and military personnel.
Washington did not immediately address those assertions but said on Tuesday the update to Russia's nuclear doctrine was no surprise and rejected "more of the same irresponsible rhetoric from Russia".
It says Russia, which sent tens of thousands of troops in to Ukraine in February 2022, is to blame for the war in Ukraine. Ukrainian President Volodymyr Zelenskiy said on Tuesday that the update showed the Russian leader's lack of interest in peace.
The U.S. shut its embassy in Kyiv on Wednesday because of "specific information of a potential significant air attack" and told its citizens in Ukraine to be ready to swiftly seek shelter. The Kremlin said it had no comment.
Naryshkin, who heads the main successor organisation to the Soviet-era KGB's First Main Directorate, said Western elites were starting to become more aware of "the seriousness of Russia's intentions."
He said the West should understand "the need for greater restraint in their actions so as not to get involved in a direct military conflict with our country, which could lead to disastrous consequences for them."
LANDMINES
Russia controls over 110,500 square km (42,660 square miles)of Ukrainian territory. Ukraine controls about 650 square km of Russia's Kursk region.
With Russian forces advancing in Ukraine, Moscow says it will achieve all its aims including the demilitarisation of Ukraine.
Biden, who gave the approval for strikes deep into Russia with American weapons, has also approved the provision of anti-personnel land mines, a U.S. official told Reuters.
"We proceed from the trend demonstrated by the outgoing U.S. administration: they are fully committed to continuing the war in Ukraine and are doing everything possible to do this in the remaining time for them," Kremlin spokesman Dmitry Peskov said.
Peskov said that while neither Russia nor the United States had signed the convention on the prohibition of anti-personnel mines, Ukraine had.
Reuters reported on Wednesday that Putin was open to discussing a ceasefire deal with U.S. President-elect Donald Trump but rules out making any major territorial concessions and says Kyiv must abandon ambitions to join NATO.
Asked about the Reuters report, Peskov said Putin was ready for contacts and negotiations but that Putin had also said he would not accept freezing the conflict.
"It is important for us to achieve our goals which are well known to everyone," Peskov told reporters.
The Kremlin also dismissed suggestions that Russia may be linked to the cutting of two fibre-optic telecommunication cables in the Baltic Sea. European officials have not directly accused Russia of destroying the cables but Germany, Poland and others said it was likely an act of sabotage.
"It's quite absurd - there is no reason to continue blaming Russia for everything," Peskov said, adding that earlier sabotage against the Nord Stream underwater gas pipelines had not been investigated with any zeal.
(Reporting by Dmitry Antonov and Guy Faulconbridge and Mark Trevelyan in London; Writing by Anastasia Teterevleva; Editing by Timothy Heritage)