US, Russia agree to keep talking amid Ukraine crisis but Putin claims concerns 'ignored'

The U.S. and Russia have agreed to keep talking amid Ukraine crisis even as Russian President Vladimir Putin claimed the U.S. has "ignored" his concerns.

The U.S. and Russia are moving ahead with their diplomatic engagements over Russia menacing Ukraine, according to senior State Department officials, after the two countries' top diplomats spoke Tuesday.

But as talks continue to proceed, there have been no results yet -- with more than 100,000 Russian troops still massed on Ukraine's borders, including increasingly in its northern neighbor Belarus.

Russian leader Vladimir Putin said the U.S. has "ignored" Russia's key demands that NATO bar Ukraine from joining and pull back allied troops from Eastern European countries -- his first comments on the crisis in over a month.

But his government is still analyzing the U.S. response to Russia, laid out in a formal proposal hand-delivered by the U.S. ambassador in Moscow last week, he said.