For most of his two decades in power, Vladimir Putin tried to get the U.S. to pay attention to his fears about NATO expanding on his doorstep.

After a massive troop buildup raised alarms Russia would invade Ukraine, U.S. President Joe Biden finally said he’s ready to talk about Putin’s security worries.

The Kremlin understands there’s virtually no chance of NATO meeting the Russian president’s demands for binding written promises not to spread further east or put its weapons near Russia, according to people close to the leadership. Just what Moscow might be willing to settle for remains unclear.