NATO is expected to discuss supplying fighter jets to Ukraine at talks this week, after Secretary-General Jens Stoltenberg warned a new major Russian offensive may have already begun.
Key points:
- Ukraine has for months been asking NATO for modern fighter jets to replace its ageing fleet
- With the first anniversary of Russia's invasion approaching, fighting in Bakhmut is intensifying
- The US embassy in Moscow urges its citizens to leave immediately "due to the risk of wrongful detentions"
"We see no sign whatsoever that President Putin is preparing for peace," Mr Stoltenberg told reporters.
"What we see is President Putin and Russia still wanting to control Ukraine.
"We see how they are sending more troops, more weapons, more capabilities."
Ukrainian President Volodymyr Zelenskyy has been pressing Western allies for fighter jets and long-range missiles to counter the feared spring offensive and to recapture lost territory.
Mr Zelenskyy last week said several countries were willing to provide Kyiv with the sought-after aircraft, but there has so far been no confirmation of any offers.
British Prime Minister Rishi Sunak had promised to train Ukrainian pilots to fly advanced NATO fighter jets, although he stopped short of offering to supply the planes.
Defence ministers from several NATO countries allied to Kyiv were due to meet in Brussels on Tuesday to discuss possible further military aid.
Ukrainian Defence Minister Oleksii Reznikov said the main items on the agenda of the talks at NATO headquarters will be air defences, forming a tank coalition, training of troops and logistical support.
"There is now a discussion going on also on the question of aircrafts and I expect that also to be addressed tomorrow at the meeting in Brussels", Mr Stoltenberg said.
Mr Stoltenberg also stressed that NATO countries supplying fighter jets to Ukraine would not make NATO part of the conflict.
Bakhmut bombarded as defenders brace for assault
The city of Bakhmut in eastern Ukraine was coming under heavy Russian artillery fire on Monday (local time) as Ukrainian forces there braced for possible ground attacks, Ukrainian military officials said.
The assault has been spearheaded by mercenaries of the Wagner group, who have made small but steady gains.
The renewed Russian bombardments made the situation there even more acute.
"The city, the city's suburbs, the entire perimeter, and essentially the entire Bakhmut direction and Kostyantynivka are under crazy, chaotic shelling," said Volodymyr Nazarenko, deputy commander of Ukraine's Svoboda battalion.
Mr Nazarenko said that although no fighting was taking place in the city centre right now, the defenders were prepared to meet any assault.
"The city is a fortress, every position and every street there, almost every building, is a fortress," he said.
Bakhmut, in the Donetsk region, is a major objective for Mr Putin and months of Russian shelling has already left much of it in ruins.
The capture of Bakhmut would give Russia a new foothold in the Donetsk region and a rare victory after several months of setbacks.
Earlier on Monday, the Russian defence ministry said its troops had pushed forward a few kilometres along the frontlines, without specifying exactly where in a war zone that encompasses several regions in the south and east.
Zelenskyy hails energy workers after latest attacks
Mr Zelenskyy has hailed efforts to restore power generation systems damaged by Russian attacks, but warned it was too early to declare victory on the energy front.
He said power workers had done such a good job repairing the damage caused by Russian missile and drone strikes on Friday that there had only been minor outages on Saturday and Sunday.
"The very fact that … after a massive missile strike this week, we can have such peaceful energy days proves the professionalism of our energy workers," he said in an evening video address.
"We have to realise [that] this is not yet a decisive victory on the energy front.
"Unfortunately, there may be new terrorist attacks from Russia. There may be new restrictions if there is further destruction or growth in consumption."
Mr Zelenskyy said scheduled energy outages would once again be in place when the working week started on Monday.
Russia has carried out repeated waves of attacks on Ukrainian energy facilities in recent months, at times leaving millions of people without light, heating or water supplies during the cold winter.
Energy Minister German Galushchenko said the power deficit after the attacks had been significantly reduced thanks to "an ultra-fast repair program" which ensured all nine nuclear power units on Ukrainian-controlled territory were working and connected to the grid.
"This is the best response of Ukrainian energy workers to enemy shelling," he said in a statement.
US tells citizens: depart Russia immediately
The United States has again told its citizens to leave Russia due to the war in Ukraine and the risk of arbitrary arrest or harassment by Russian law enforcement agencies.
"US citizens residing or travelling in Russia should depart immediately," the US embassy in Moscow said.
"Exercise increased caution due to the risk of wrongful detentions."
"Do not travel to Russia," the embassy warned.
The US last issued a similar public warning was in September after Russian President Vladimir Putin ordered a partial mobilisation.
"Russian security services have arrested US citizens on spurious charges, singled out US citizens in Russia for detention and harassment, denied them fair and transparent treatment, and convicted them in secret trials or without presenting credible evidence," the embassy said.
"Russian authorities arbitrarily enforce local laws against US-citizen religious workers, and have opened questionable criminal investigations against US citizens engaged in religious activity."
Russia has opened a criminal case against a United States citizen on suspicion of espionage, the Federal Security Service said in January.
Reuters/ABC