MOSCOW >> Russian President Vladimir Putin today accused the U.S. and its allies of ignoring Russia’s top security demands but said Moscow is willing to talk more to ease tensions over Ukraine.

The comments were his first on the standoff in more than a month and suggested a potential Russian invasion of Ukraine may not be imminent and that at least one more round of diplomacy is likely.

Yet the two sides remain unyielding in their main positions, and there was little apparent hope for concessions. Russia is expected to respond soon to a U.S. proposal for negotiations on lesser Russian demands after which Russian Foreign Minister Sergey Lavrov and U.S. Secretary of State Antony Blinken will speak.

Lavrov and Blinken spoke today and reiterated positions put forward by Putin and President Joe Biden. The White House said Biden and Putin could also speak once the U.S. receives Russia’s response.

In remarks to reporters at a Moscow news conference with the visiting leader of NATO ally Hungary, Putin said the Kremlin is still studying the U.S. and NATO’s response to the Russian security demands received last week. But he said it was clear that the West has ignored Russian demands that NATO not expand to Ukraine and other ex-Soviet nations, refrain from deploying offensive weapons near Russia and roll back its deployments to Eastern Europe.

Putin argued that it’s possible to negotiate an end to the standoff if the interests of all parties, including Russia’s security concerns, are taken into account. “I hope that we will eventually find a solution, although we realize that it’s not going to be easy,” Putin said.

Russia has amassed over 100,000 troops along the border of Ukraine, fueling fears of an invasion. It has denied any intention to attack.

Washington and its allies have rejected Moscow’s key demands. They emphasize that Ukraine, like any other nation, has the right to choose alliances, although it is not a NATO member now and is unlikely to join any time soon.

Putin said the Western allies’ refusal to meet Russia’s demands violates their obligations on the integrity of security for all nations. He warned that a Ukrainian accession to NATO could lead to a situation where Ukraine launches military action to reclaim control over Russian-annexed Crimea or areas controlled by Russia-backed separatists in the country’s east.

“Imagine that Ukraine becomes a NATO member and launches those military operations,” Putin said. “Should we fight NATO then? Has anyone thought about it?”

Russia annexed Ukraine’s Crimean Peninsula in 2014 following the ouster of the country’s Moscow-friendly president and later threw its weight behind rebels in Ukraine’s eastern industrial heartland, triggering a conflict that has killed over 14,000 people.

Putin charged that while the U.S. airs concerns about Ukraine’s security, it is using the ex-Soviet country as an “instrument” in its efforts to contain Russia.

He alleged that Washington may try to “draw us into a military conflict and force its allies in Europe to impose the tough sanctions the U.S. is talking about now.” Another possible option would be to “draw Ukraine into NATO, deploy offensive weapons there” and encourage Ukrainian nationalists to use force to reclaim the rebel-held east or Crimea, “drawing us into a military conflict,” Putin claimed.

Speaking after talks with Hungarian Prime Minister Victor Orban, who has forged closer ties with Moscow than almost any other NATO member, Putin noted that it’s still possible to negotiate a settlement that would take every party’s concerns into account.

“We need to find a way to ensure interests and security of all parties, including Ukraine, European nations and Russia,” Putin said, emphasizing that the West needs to treat Russian proposals seriously to make progress.

He said French President Emmanuel Macron may soon visit Moscow as part of renewed diplomatic efforts following their call on Monday.

In a bid to exert pressure on the West, Lavrov sent letters to the U.S. and other Western counterparts pointing out their past obligations signed by all members of the Organization for Security and Cooperation in Europe, a top trans-Atlantic security grouping.

Russia has argued that NATO’s expansion eastward has hurt Russia’s security, violating the principle of “indivisibility of security” endorsed by the OSCE in 1999 and 2010. It says the U.S. and its allies have ignored the principle that the security of one nation should not be strengthened at the expense of others, while insisting on every nation’s right to choose alliances.

In his letter, which was released by the foreign ministry, Lavrov said “there must be security for all or there will be no security for anyone.” And in his call with Blinken, Lavrov warned that Moscow will not allow Washington to “hush up” the issue.

Blinken, meanwhile, emphasized “the U.S. willingness, bilaterally and together with Allies and partners, to continue a substantive exchange with Russia on mutual security concerns.” However, State Department spokesman Ned Price said Blinken was resolute in “the U.S. commitment to Ukraine’s sovereignty and territorial integrity, as well as the right of all countries to determine their own foreign policy and alliances.”

Blinken “urged immediate Russian de-escalation and the withdrawal of troops and equipment from Ukraine’s borders,” Price said. He reaffirmed that “further invasion of Ukraine would be met with swift and severe consequences and urged Russia to pursue a diplomatic path.”

Senior State Department officials described the call as professional and “fairly candid,” noting that if Russia wanted to prove it isn’t going to invade Ukraine, it should withdraw its troops from the border and neighboring Belarus.

Shortly after speaking to Lavrov, Blinken convened a conference call with the secretary general of NATO, the EU foreign policy chief and the chairman-in-office of the OSCE as part of efforts to ensure that the allies are engaged in any further contacts with Russia.

Speaking to reporters at the United Nations, Russia’s U.N. ambassador, Vassily Nebenzia, said the U.S. statement about its readiness for dialogue “doesn’t correlate” with Washington sending planeloads of military equipment to Ukraine.

“I don’t know why the U.S. is escalating tensions and at the same time accusing Russia,” he said.

British Prime Minister Boris Johnson visited Kyiv for scheduled talks with Ukrainian President Volodymyr Zelenskyy. Johnson said the U.K. has a package of measures including sanctions ready to go “the moment the first Russian toecap crosses further into Ukrainian territory.”

“It is vital that Russia steps back and chooses a path of diplomacy, and I believe that is still possible,” Johnson said. “We are keen to engage in dialogue, of course we are. But we have the sanctions ready.”

He said he would have a call with Putin on Wednesday, noting that the Russian leader was trying to “impose a new Yalta, new zones of influence” in a reference to the 1945 deal between the allied powers. “And it would not just be Ukraine that was drawn back into the Russian sphere of influence,” Johnson added.

In other developments, Biden was expected to nominate career foreign service officer Bridget Brink to assume the long-vacant diplomatic post of American ambassador to Ukraine, according to a U.S. official familiar with the decision. Brink currently serves as the ambassador to Slovakia.