Russia said it would not make concessions under U.S. pressure and warned that this week s talks on the Ukraine crisis might end early, while Washington said no breakthroughs were expected and progress depended on de-escalation from Moscow.
The hard line from Moscow underscored the fragile prospects for negotiations that Washington hopes will prevent a Russian invasion of Ukraine, at the tensest point in U.S.-Russian relations since the Cold War ended three decades ago.
Talks begin on Monday in Geneva before moving to Brussels and Vienna, but the state-owned RIA news agency said Deputy Foreign Minister Sergei Ryabkov said it was entirely possible that the diplomacy could end after a single meeting.
He stated that he can't rule out anything, this is an entirely possible scenario and the Americans should have no illusions about this.
"We will not make any concessions under pressure or amid constant threats from participants in the talks," said Ryabkov, who will lead the Russian delegation in Geneva.
Interfax news agency quoted Ryabkov as saying that Moscow was not optimistic going into the talks.
The U.S. prognosis was similarly gloomy.
I don't think we're going to see any breakthroughs in the coming week, Secretary of State Antony Blinken said in a CNN interview.
In response to Russian demands for Western security guarantees, the United States and allies have said they are prepared to discuss the possibility of each side restricting military exercises and missile deployments in the region.
Both sides will put proposals on the table and then see if there are grounds for moving forward, Blinken said.
It is very hard to see that happening when Russia has a gun to the head of Ukraine with 100,000 troops near its borders, when there is an ongoing escalation, when that happens, Blinken said in an interview with ABC News.
Ahead of the formal talks, U.S. Deputy Secretary of State Wendy Sherman met with Ryabkov on Sunday in Geneva and told him Washington would welcome genuine progress through diplomacy, the State Department said.
Ryabkov told reporters his meeting with Sherman had been complex but businesslike, Russian new agency Interfax said.
Tens of thousands of Russian troops are gathered within a few miles of Ukraine in preparation for what Washington and Kyiv say could be an invasion, eight years after Russia seized the Crimea peninsula from Ukraine.
Russia s Ryabkov, who compared the situation to the 1962 Cuban missile crisis when the world was on the brink of nuclear war, was consistent with the uncompromising line Russia has been signalling for weeks.
Russia denies that it plans to join NATO and is responding to what it calls aggressive and provocative behavior from the NATO military alliance and Ukraine, which has tilted toward the West and aspires to join NATO.
Russia sent troops into neighboring Kazakhstan last week after the former Soviet republic was hit by a wave of unrest. Russia's Foreign Ministry reacts furiously on Saturday to a jibe by Blinken that once Russians are in your house, it is sometimes very hard to get them to leave. Russia presented a sweeping set of demands last month including a ban on further NATO expansion and an end to the alliance's activities in Central and Eastern European countries that joined it after 1997.
Large parts of the Russian proposals have been dismissed by the United States and NATO as nonstarters.
The United States was not willing to pull some U.S. troops out of Eastern Europe or rule out expanding NATO to include Ukraine, Blinken said.
Russia seems unlikely to make a major climb down to abandon its demands for a more limited agenda, especially after weeks of troop movements near Ukraine and a series of tough statements from President Vladimir Putin.
The Kremlin leader said that after successive waves of NATO expansion it is time for Russia to enforce its red lines and ensure that the alliance does not admit Ukraine or station weapons systems there that would target Russia.
Ukraine promised in 2008 that it would be allowed to join one day, but diplomats say there is no possibility that that will happen soon.
NATO said it is a defensive alliance and Moscow has nothing to fear from it. That is far from Putin's view of Russia, which sees Russia as under threat from Western powers, he says he has broken promises as the Cold War ended not to expand its borders. The United States and its allies dispute that such pledges were given.
In two conversations over the past five weeks, U.S. President Joe Biden warned Putin that Russia would face unprecedented economic sanctions in the event of further aggression against Ukraine. The European Union and the Group of Seven nations have joined in threatening massive consequences. Putin said that would lead to a complete rupture of relations.
Russia is due to hold negotiations with NATO in Brussels on Wednesday and the OSCE in Vienna on Thursday in addition to the Geneva talks.