Russian President Vladimir Putin warned Wednesday that the war in Ukraine could go on for a long time, and said nuclear tensions had risen because of it.
Speaking more than nine months after his forces invaded, the Russian leader gave no sign of any intent to let up in the battle, as intense shelling continued along the front in eastern Ukraine.
"Of course, it might be a lengthy process," he told a meeting of the Kremlin's human rights council.
Ukrainian President Volodymyr Zelensky -- who was declared Time magazine's iconic "Person of the Year" on Wednesday for his "defense of freedom" -- said six people were killed in the latest Russian strikes, this time on a village in the frontline region of Donetsk.
That came a day after Ukrainian artillery strikes killed six people in the Russian-occupied regional capital city of Donetsk, according to local officials.
- Nuclear rhetoric -
In the Kremlin meeting, Putin appeared to caution against expectations of any early resolution of the conflict, repeating that it would be a long process.
But he sparked fresh concerns in the West as he broached anew the issue of whether the war could escalate to the use of nuclear weapons.
Putin, who has previously hinted at use of small tactical weapons in the war, remained evasive on his intentions.
"Such a threat is rising. Why make a secret out of it here?" he said.
"Russia will under no circumstances use them first," Putin said.
"But if it does not use them first under any circumstances, then it will not be the second to use them either, because the possibilities of using them in the event of a nuclear strike against our territory are very limited," he said.
US State Department spokesman Ned Price condemned the nuclear talk, as vague as it was.
"We think any loose talk of nuclear weapons is absolutely irresponsible," Price told reporters.
"It is dangerous, and it goes against the spirit of that statement that has been at the core of the nuclear non-proliferation regime since the Cold War," he said.
- Azov Sea -
After more that nine months of war, Russian forces have missed most of their key military goals including toppling the Ukrainian government, capturing the Donbas region and annexing four territories.
Nevertheless, Putin told the meeting that the Ukraine lands that Russian forces have occupied and declared annexed were a "significant result" of the military campaign.
He made special reference to Russia's control now of all the land along the Azov Sea.
"The Azov Sea has become an internal sea to the Russian Federation, that's a serious thing," he noted.
But he promised there would not be a new wave of mobilisation, amid domestic Russian fears of a new callup. Western officials say Russian troops have taken heavy personnel and equipment losses in recent fighting.
"Out of 300,000 of our mobilised fighters, our men, defenders of the fatherland, 150,000 are in the area of operations," including 77,000 in combat units, he said.
- Person of the Year -
Meanwhile, Zelensky basked in unwavering support from the West as Time chose him as its most important global figure for 2022 -- a title Putin himself received in 2007.
"Whether the battle for Ukraine fills one with hope or with fear, Volodymyr Zelensky galvanized the world in a way we haven't seen in decades," said Time editor in chief Edward Felsenthal.
"In the weeks after Russian bombs began falling on Feb. 24, his decision not to flee Kyiv but to stay and rally support was fateful," he said.
But one day after traveling to Sloviansk near the eastern front line, the Ukraine leader was focused one the newest impact on his country.
"Terrorists attacked the peaceful city of Kurakhove," he said in a statement on social media.
"A market, a bus station, gas stations, and residential buildings came under fire. At least six civilians were killed, five were wounded."