VIENNA — Russian officials signaled that they could abandon diplomatic efforts to resolve the security crisis surrounding Ukraine, bringing a whirlwind week of European diplomacy to an ominous end and deflating hopes that negotiators could forge a path toward easing tensions in Eastern Europe.
One senior Russian diplomat said that talks with the West were approaching a “dead end,” while another said the Kremlin would wait until it receives written responses next week to its demands from Washington and from NATO before deciding how to proceed.
It was clear that Russia’s next move would be up to President Vladimir V. Putin, who, his spokesman said on Thursday, was being briefed regularly this week on negotiations with the West.
