Ukrainian President Volodymyr Zelensky warned that Russia was likely to intensify its "hostile activity" this week, as Kyiv awaits a historic decision from the European Union on its membership application.
Nearly three months after Russia launched a bloody invasion of his country, Zelensky said there had been "few such fateful decisions for Ukraine" as the one it expects from the EU this week.
"Only a positive decision is in the interests of the whole of Europe," he said in his evening address Sunday.
"Obviously, we expect Russia to intensify hostile activity this week ... We are preparing. We are ready," he continued.
Moscow's forces have been pummelling eastern Ukraine for weeks as they try to seize the Donbas region, after being repelled from other parts of the country following their February invasion.
On Friday, Brussels backed Kyiv's bid for EU candidate status after the heads of the bloc's biggest members -- France, Germany and Italy -- paid a visit to the Ukrainian capital.
Ukraine could join the list of countries vying for membership as early as this week, when member state leaders meet at a Brussels summit.
NATO's chief Jens Stoltenberg meanwhile warned that the war could grind on "for years" and urged Western countries to be ready to offer long-term military, political and economic aid.
"We must not weaken in our support of Ukraine, even if the costs are high -- not only in terms of military support but also because of rising energy and food prices," Stoltenberg told German daily newspaper Bild.
Ukraine has repeatedly urged Western countries to step up their deliveries of arms, despite warnings from nuclear-armed Russia that it could trigger wider conflict.
- Residents rally -
Zelensky made a rare trip outside Kyiv Saturday to the hold-out Black Sea city of Mykolaiv, where he visited troops nearby and in the neighbouring Odessa region for the first time since the invasion.
"We will not give away the south to anyone, we will return everything that's ours and the sea will be Ukrainian and safe," he said in a video posted on Telegram as he made his way back to Kyiv.
Russia's defence ministry said Sunday it launched missile strikes during the past 24 hours, with one attack on a top-level Ukrainian military meeting near the city of Dnipro killing "more than 50 generals and officers".
It said it also targeted a building housing Western-provided weapons in Mykolaiv, destroying Ukrainian artillery and armoured vehicles.
There was no independent verification of the claims.
Mykolaiv is a key target for Russia as it lies on the route to the strategic port of Odessa.
With Russia maintaining a blockade of Odessa that has trapped grain supplies and threatens a global food crisis, residents have turned their attention to rallying the home front effort.
"Every day, including the weekend, I come to make camouflage netting for the army," said Natalia Pinchenkova, 49, standing by a large Union flag, a show of thanks to Britain for its support for Ukraine.
- 'So many killed' -
The Ukraine war is fuelling not only a global food crisis but an energy crisis too.
Hit by punishing sanctions, Moscow has turned up the pressure on European economies by sharply reducing gas supplies, which has in turn sent energy prices soaring.
Germany on Sunday announced emergency measures including increased use of coal to ensure it meets its energy needs after a drop in the supply of Russian gas.
Austria announced it will reopen a mothballed coal power station to combat shortages, and Italian company Eni joined a huge Qatari project to expand production from the world's biggest natural gas field.
The worst of the fighting is in the industrial Donbas region, with battles raging in villages outside the city of Severodonetsk, under unrelenting Russian fire for weeks.
Ukraine's armed forces said Sunday they had pushed back Russian attacks on villages near Severodonetsk.
Lysychansk, which sits across a river from Severodonetsk, is also under heavy bombardment.
Some residents have taken shelter in basements in dire conditions, with limited supplies of food and water.
Natalia Khalaimova, 54, urged Russia and Ukraine to negotiate an end to the war.
"Every war in any country ends -- but the sooner, the better," she told AFP. "So many civilians are killed. Most of them were not involved in the war at all."