GENEVA (AP) — The United States and Russia locked horns over Ukraine and other security issues Monday with no sign of progress from either side at highly anticipated strategic talks.

Low expectations from both Washington and Moscow about the high-stakes session in Geneva appeared to have been met as senior diplomats from the two countries emerged without offering any hint of success.

Neither characterized the meeting as a complete failure, but neither did they offer any easing of the increasingly worrisome standoff over Russia’s military buildup on its border with Ukraine that the West sees as a fundamental threat to European security. Nor was there any indication of movement on other, perhaps less-explosive matters that have vexed the U.S.-Russia relationship.

Moscow insists on guarantees to halt NATO’s eastward expansion and even roll back the military alliance’s deployments in Eastern Europe, while Washington firmly rejects the demands as a nonstarter.

With both sides dug in on their positions and Ukraine’s future hanging in the balance, Russian Deputy Foreign Minister Sergei Ryabkov said “no progress” was made on the central demand on NATO expansion, although he insisted: “We have no intention to invade Ukraine.”

Ryabkov spoke following talks with his U.S. counterpart, Wendy Sherman — part of a flurry of diplomatic activity in Europe this week aimed at defusing the tensions.

Sherman called the talks a “frank and forthright discussion.”

“It was not what you would call a negotiation,” she told reporters. “We’re not to a point where we’re ready to set down texts and begin to go back and forth.”

“We were firm, however, on pushing back on security proposals that are simply nonstarters for the United States,” Sherman said, adding “we will not allow anyone” to shut NATO’s “open-door policy” that extends to countries seeking to join the alliance.

She said Washington “will not forgo bilateral cooperation with sovereign states that wish to work with the United States. And, we will not make decisions about Ukraine without Ukraine, about Europe without Europe or about NATO without NATO.”

Russian President Vladimir Putin has described NATO expansion to Ukraine and other former Soviet states as a “red line” for Moscow, demanding binding guarantees from the West that they wouldn’t become members of the alliance.

Moscow has sought to wrest a string of concessions from the U.S. and its Western allies, and has massed an estimated 100,000 troops near Ukraine in steps that have raised concerns about a possible military intervention there.

“The situation now is so dangerous, and so — I would say — precarious that we cannot afford any further delays in resolution of this very fundamental question,” Ryabkov said at a separate news conference at the Russian mission. “As President Putin said, on many occasions, ‘we cannot backpedal. We cannot go backwards. There is no further space for us to do so.’”

Ryabkov rattled off Russian concerns and demands issued last month on subjects like NATO expansion and wanting Western commitments not to deploy offensive weapons near Russian borders.

“The American side has treated the Russian proposals seriously and deeply studied them,” he said, adding that he characterized Moscow’s demand for legally binding guarantees that NATO would not move eastward as “an absolute imperative for us.”

Ryabkov emphasized that it would be hard to work on other issues if the U.S. stonewalled on Russia’s key demands.

“If now NATO proceeds towards deployment of capabilities that are being developed very rapidly in the U.S., and will possibly be introduced somewhere in Europe, it would require a military response on the Russian part, that is a decision to counter this threat through means at our discretion,” said Ryabkov, speaking in English. “That will inevitably, unavoidably damage security of the U.S. and its European allies.”

He did not elaborate.

Echoing similar comments from U.S. Secretary of State Antony Blinken, Sherman said progress could only happen if Russia “stays at the table and takes concrete steps to de-escalate tensions.”

“We’ve made it clear that if Russia further invades Ukraine there will be significant costs and consequences well beyond what they faced in 2014,” she said. “Russia has a stark choice to make.”

The meeting was part of “Strategic Security Dialogue” talks on arms control and other broad issues launched by Putin and U.S. President Joe Biden at a June summit in the Swiss city. Talks between Russia and NATO are planned Wednesday in Brussels followed by a meeting in Vienna of the Organization for Security and Cooperation in Europe on Thursday.

The U.S. has played down hopes of significant progress and said some Russian demands — like a possible halt to NATO expansion — go against countries’ sovereign rights to set up their own security arrangements and are nonnegotiable.

But U.S. officials have expressed openness to other ideas, like curtailing possible future deployments of offensive missiles in Ukraine and putting limits on American and NATO military exercises in Eastern Europe — if Russia is willing to back off on Ukraine.

Blinken said Sunday he didn’t expect any breakthroughs, with a more likely positive outcome being an agreement to de-escalate tensions in the short term and return to talks at an appropriate time in the future. But the U.S. will have to see a de-escalation for there to be actual progress.

“It’s very hard to see that happening when there’s an ongoing escalation, when Russia has a gun to the head of Ukraine with 100,000 troops near its borders, the possibility of doubling that on very short order,” Blinken said on ABC’s “This Week.”

NATO Secretary-General Jens Stoltenberg also sought to play down expectations earlier Monday.

“I don’t think that we can expect that these meetings will solve all the issues,” he told reporters in Brussels after talks with Olga Stefanishyna, Ukraine’s deputy prime minister for European and Euro-Atlantic Integration. “What we are hoping for is that we can agree on a way forward, that we can agree on a series of meetings, that we can agree on a process.”

During a visit to Rome, German Foreign Minister Annalena Baerbock said dialogue offered the only way out of the crisis.

“At the same time, it’s equally clear that a renewed breach of Ukrainian sovereignty by Russia would have grave consequences,” she told reporters.

Russia has said it wants the issue resolved this month, but NATO is wary that Putin might be looking for a pretext, such as a failure in the negotiations, to launch an invasion.

The United States, which has emphasized that Ukraine’s government and those of other European countries need to part of the discussions, “will not discuss European security without our European allies and partners,” State Department spokesman Ned Price said Sunday.

Thomas Greminger, director of the Geneva Center for Security Policy, said the talks hadn’t revealed much new — but were a start.

“But I think what has happened now, these issues are on the radar of everybody and they are on the discussion and hopefully soon also on the negotiation table,” he said in an interview. “And that is important. And in that sense, for me, that is the progress.” ___

Lee reported from Washington. Jamey Keaten in Geneva, Vladimir Isachenkov in Moscow, Lorne Cook in Brussels and Frank Jordans in Berlin contributed.