Even without any American concessions, Monday’s talks already represented a victory of sorts for the Kremlin because they brought the issue of NATO expansion, which has long angered Mr. Putin, to the forefront of issues confronting Washington policymakers.

Ms. Liik, the analyst, said the seriousness with which the United States appeared to prepare for Monday’s talks — sending a large delegation that included officials from the Defense Department, the State Department and the National Security Council, which coordinates policy at the White House — sent an important signal to Moscow.

“We had the feeling that the American side took the Russian proposals very seriously and studied them deeply,” Mr. Ryabkov said. “Now, things are being called by their names, and this in itself has a healing effect on our relations with the West.”

Mr. Ryabkov said Russia would make a decision on whether or not to continue diplomacy after the meetings this week, warning that “the risks connected with a possible intensification of confrontation cannot be underestimated.”

But Mr. Ryabkov was vague as to what, exactly, the consequences would be if the United States refused Russia’s demands. He repeatedly said that Russia had no plans to attack Ukraine and that there was “no reason to fear an escalation scenario in this regard.”

But he also said that increased military activity by the West in Ukraine and in the Black Sea region had caused Russia to shift its military posture in the region, and that it was concerned about “deliberate provocations” by Ukraine.

Western officials have said they believe that Russia could manufacture a “provocation” as a pretext for an invasion.

Describing the consequences of what would happen if diplomacy fails, Mr. Ryabkov repeated Mr. Putin’s wording that the West would face a “military-technical response” by Russia. He said Russia would not make public what that response would look like because doing so would invite new sanctions threats, but he indicated it could involve new deployments of certain weapons systems.

Ms. Sherman, cautious after a long career of sparring with Russian officials, was asked after the meeting whether she had realistic hope for a diplomatic solution.

“It’s very hard for diplomats to do the work we do if you have no hope,’’ she said. “So of course I have hope.”

She paused briefly. “But what I care about more is results.”

View Source

>>> Don’t Miss Today’s BEST Amazon Deals! <<<<