MOSCOW — Even as the world’s top diplomats were gingerly drafting a tentative accord to “de-escalate tensions” in Ukraine, President Vladimir V. Putin was on national television here, brashly declaring Russia’s historical claims over Ukrainian territory, reiterating a threat to use military force and generally sounding a defiant, even mocking, tone toward the United States.

Mr. Putin, appearing cool and confident during a four-hour question-and-answer show, referred repeatedly to southeast Ukraine as “New Russia” — a historical term for the area north of the Black Sea that the Russian Empire conquered in the 1700s. And, he said, only “God knows” why the region became part of Ukraine in the 1920s, signaling that he would gladly correct that error.

Dropping previous pretenses, he calmly acknowledged for the first time that Russian troops had been deployed to occupy and annex Crimea. And in perhaps the day’s most astonishing moment, he took evident delight in fielding a prerecorded question from Edward J. Snowden, the fugitive American who is wanted on espionage charges for leaking documents on surveillance programs.