Russian President Vladimir Putin on Thursday accused NATO of massive expansion to the east with no regards for his country's security interests, while Washington signalled preparedness to discuss some of the issues he raised.
There have already been "five waves of expansion" despite assurances that the Western military alliance would not endanger Russian security, Putin said at his annual press conference in Moscow.
He was particularly critical of Ukraine's possible admission to NATO. Russian troops have built up along Ukraine's border in recent weeks.
"Another NATO expansion eastward is unacceptable. What's not to understand about it?" the Kremlin leader asked. "We want to consolidate our security."
Asked if he could guarantee that Russia would not invade Ukraine, Putin said his country would act as its security interests demanded.
At the same time, he touted his proposals for binding security guarantees. "There can be no tricks here," he said.
Russia handed a draft agreement to NATO, the United States and its allies last week. In it, Moscow calls for an end to NATO's eastward expansion, which it sees as threatening.
During his press conference, Putin mentioned he would engage with the US early next year, plans also confirmed by Washington.
NATO talks with Russia
NATO Secretary General Jens Stoltenberg also said in an interview that he was willing to talk with Russia to help ease tensions but that there would be no compromises on basic principles.
The US said it was ready to discuss Ukraine with Russia in January, as well as Moscow's demands for security guarantees.
"We've said both publicly and to the Russian government we'll prepare to meet in early January," a senior White House official said on Thursday, adding that no date or location had been set.
The US is prepared to engage diplomatically through multiple channels beginning in early January, however the details have not been finalized, according to spokesperson Jen Psaki. She underlined Washington's general willingness to engage.
Of the content of possible talks, the White House said Moscow's demands for additional security guarantees would also be discussed.
Some things had been proposed "that we will never agree to," the senior official said. "I think the Russians probably know that at some level."
Putin, for his part, insisted that Russia does not want a conflict with Ukraine, in his comments to the press.
In the past, he has repeatedly called the neighbouring country an artificial entity. NATO, the EU and the US all repeatedly emphasise Ukraine's independence and territorial integrity, after Moscow annexed Crimea in 2014.
Russia supports pro-Russian separatists in eastern Ukraine and on Thursday, Putin said he had the impression that Kiev was planning a military operation against the breakaway parts of the Luhansk and Donetsk regions.
He said he hoped that the crisis could be resolved peacefully, and that the people of Donbas should be able to determine their future themselves.
Putin also maintained his refusal to call Russia a party to the conflict.
Meanwhile the Organisation for Security and Cooperation in Europe said those involved in the conflict wanted to make a new attempt to stick to the ceasefire, and that it had received assurances that the agreements would be implemented "in full."
Putin addressed several other contentious issues during the press conference, including an attack on his political opponent Alexei Navalny, which was heavily criticized by the West.
Putin called for evidence of a crime, saying in more than a year, no one had presented evidence of the "alleged poisoning" with the chemical agent Novichok. "Nothing. Zero," Putin said.
His comments came despite several laboratories, including one run by the German armed forces, having provided evidence of the poisoning.
A spokesperson for the jailed Navalny, Kira Yarmysh, took to Twitter to call Putin a "coward" and a "murderer."
The Kremlin chief also defended the controversial crackdown on dissidents and so-called "foreign agents," which have included non-governmental organizations and media groups.
He said Russia was too big to be influenced from the outside.
"You can only corrode it from within," he added.
Putin did make one major concession in the press conference, calling for punishment following the publication of numerous videos of torture in Russian detention centres.
"These are crimes that must be solved," Putin said.
The Kremlin said it had allowed up to 500 domestic and international journalists to attend Putin's annual press conference. Last year's event was more scaled back because of the pandemic.
Analysts say Russians are increasingly dissatisfied with Putin's policies amid high prices, unemployment and low incomes.
He has led the country as president or prime minister for more than 20 years.