Russian President Vladimir Putin said Tuesday that the U.S. and its allies have ignored his nation's top security demands but insisted that Moscow is still open for more talks with the West on easing soaring tensions over Ukraine.

Putin noted that the U.S. and its allies have ignored the Kremlin’s demands for guarantees that NATO won’t expand to Ukraine, won’t deploy weapons near the Russian border, and will roll back its forces from Eastern Europe.

Putin said he hoped dialogue would continue in order to avoid "negative scenarios" including war.

At a news conference, Putin raised the possibility of war between Russia and NATO if Ukraine joined the alliance and then attempted to take back Crimea from Russia by force.

"Let's imagine Ukraine is a NATO member and starts these military operations. Are we supposed to go to war with the NATO bloc? Has anyone given that any thought? Apparently not," he said.

Putin said ways needed to be found to protect everyone's security.

This report is contains material compiled from Newsmax wire services, includ Reuters and The Associated Press.