Russian forces pounded targets in eastern and southern Ukraine with missiles, drones and artillery, Ukraine's General Staff said on Monday, while millions remained without power in subzero temperatures after further strikes on key infrastructure.
In a flurry of weekend diplomacy, Ukraine's President Volodymyr Zelensky spoke with the leaders of the United States, France and Turkey ahead of planned Group of Seven (G7) and EU meetings on Monday that could agree on further sanctions on Russia.
There are no peace talks and no end in sight to the deadliest conflict in Europe since World War Two, which Moscow describes as a "special military operation" and Ukraine and its allies call an unprovoked act of aggression.
Russia does not yet see a "constructive" approach from the United States on the Ukraine conflict, RIA news agency quoted Deputy Foreign Minister Sergei Vershinin as saying on Monday. The two countries have held a series of contacts in Turkey.
US President Joe Biden told Zelensky during a call on Sunday that Washington was prioritizing efforts to boost Ukraine's air defenses, the White House said. Zelensky said he had thanked Biden for the "unprecedented defense and financial" help the United States has provided.
On the ground in Ukraine, the Black Sea port of Odesa on Monday resumed operations that had been suspended after Russia used Iranian-made drones on Saturday to hit two energy facilities. Power is slowly being restored to some 1.5 million people, officials said.
Zelensky said other areas experiencing "very difficult" conditions with power supplies included the capital Kyiv and Kyiv region and four regions in western Ukraine and the Dnipropetrovsk region in the center of the country.
There were no reports of fresh strikes or blackouts overnight into Monday.
In its daily update on the military situation around the country, Ukraine's General Staff said its forces had repelled Russian assaults on four settlements in the eastern Donetsk region and on eight settlements in the adjacent Luhansk region.
Russia kept up its attacks on Bakhmut, which is now largely in ruins, Avdiivka, and Lyman, and launched two missile strikes against civilian infrastructure in Kostyantynivka, all in the Donetsk region - one of four that Moscow claims to have annexed from Ukraine after "referendums" branded illegal by Kyiv.
Elsewhere, Russian forces carried out more than 60 attacks from rocket salvo systems targeting the civilian infrastructure in Kherson, the southern city liberated by Ukrainian forces last month, and Ukrainian troops based there, the General Staff said.
Russia also shelled settlements along the Zaporizhzhia frontline in southern central Ukraine, it said, while Ukrainian forces hit Russian control points, munitions warehouses and other targets.
Reuters could not independently verify the battlefield accounts.
On the diplomatic front, European Union foreign ministers were due to discuss a ninth package of sanctions on Russia over its invasion of Ukraine that would place almost 200 more individuals and entities on the EU sanctions list.
However, EU foreign policy chief Josep Borrell stressed there was still no agreement on the package at this stage, adding that he hoped that could come later on Monday or on Tuesday. The ministers will also discuss an additional 2 billion euros ($2.11 billion) worth of arms deliveries to Ukraine.
Separately, Germany's Chancellor Otto Scholz will hold an online meeting with other G7 leaders on Monday about the situation in Ukraine that Zelensky is also expected to address. Scholz is set to give a news conference afterwards at 1630 GMT.
"We are constantly working with partners," Zelensky said on Sunday after talking to Biden, France's Emmanuel Macron and Turkey's Recep Tayyip Erdogan, adding that he expects some "important results" from the upcoming international meetings on Ukraine.
US Treasury Secretary Janet Yellen told CBS's "60 Minutes" Washington's support for Ukraine's military and economy - more than $50 billion and counting - would continue "for as long as it takes" and reiterated that ending the war was the single best thing the United States could do for the global economy.
Zelenskyy said he had held "very specific" talks with Erdogan on assuring Ukraine's grain exports.
Turkey, which acted as a mediator in peace talks in the early months of the war, also worked alongside the United Nations in a grain deal, which opened up Ukrainian ports for exports in July after a six-month de facto Russian blockade.
Erdogan's office said the Turkish leader also had a call with Russian President Vladimir Putin on Sunday, in which he had called for a quick end to the conflict.
Putin said last week that Moscow's near-total loss of trust in the West would make an eventual settlement over Ukraine much harder to reach and warned of a protracted war.
Moscow shows no signs of being ready to respect Ukraine's sovereignty and pre-war borders, saying the four regions it claims to have annexed from Ukraine in September are part of Russia "forever." The government in Kyiv has ruled out conceding any land to Russia in return for peace.