President Volodymyr Zelenskiy said on Friday Ukraine had reached a "strategic turning point" in the conflict with Russia, but Russian forces bombarded cities across the country and appeared to be regrouping for a possible assault on the capital Kyiv.
The governor of the Kharkiv region, on the Russian border, said a psychiatric hospital had been hit, and the mayor of the city of Kharkiv said about 50 schools had been destroyed there.
In the besieged southern city of Mariupol, the city council said at least 1,582 civilians had been killed as a result of Russian shelling and a 12-day blockade that has left hundreds of thousands trapped with no food, water, heat or power.
Russia's defence ministry said the Black Sea port was now completely surrounded and Ukrainian officials accused Russia of deliberately preventing civilians getting out and humanitarian convoys getting in.
A new effort to evacuate civilians along a humanitarian corridor appeared to have failed.
"The situation is critical," Ukrainian interior ministry adviser Vadym Denysenko said.
Western countries meanwhile took more steps to try to force Russian President Vladimir Putin to end his assault on Ukraine.
U.S. President Joe Biden said the G7 industrialised nations would revoke Russia's "most favoured nation" trade status. He also announced a U.S. ban on imports of Russian seafood, alcohol and diamonds.
European Union leaders meeting in France said they were ready to impose harsher economic sanctions on Russia and might give Ukraine more funds for arms. But they rejected Ukraine's request to join the bloc.
At a meeting with Belarus President Alexander Lukashenko, Putin said there were "certain positive shifts" in talks with Kyiv, but did not elaborate.
Gearing up
With the Russian assault now in its third week, Zelenskiy, who has rallied his people with a series of addresses, said Ukraine had "already reached a strategic turning point".
"It is impossible to say how many days we still have (ahead of us) to free Ukrainian land. But we can say we will do it," he said. "We are already moving towards our goal, our victory."
Russia's main attack force has been stalled on roads north of Kyiv, having failed in what Western analysts say was an initial plan for a lightning assault.
But images released by private U.S. satellite firm Maxar showed armoured units manoeuvring in and through towns close to an airport on Kyiv's northwest outskirts, site of fighting since Russia landed paratroopers there in the first hours of the war.
Other elements had repositioned near the settlement of Lubyanka just to the north, with artillery howitzers in firing positions, Maxar said.
Britain's Defence Ministry said Russia appeared to gearing up for new offensive activity in the coming days that would probably include operations against Kyiv.
However, the Russian ground forces were still making only limited progress, hampered by logistical problems and Ukrainian resistance, it said in its intelligence update.
The Ukrainian general staff said Russian forces were regrouping after taking heavy losses. Ukrainian troops had pushed some back to "unfavourable positions" near the Belarus border to the rear of the main Russian column, it said.
"Our opponent has been halted in practically every direction by air strikes, rocket fire and ground attacks," presidential adviser Oleksiy Arestovych told a news briefing.
He said Ukrainian fighters had staged counter-attacks near Kyiv and in Kharkiv.
Kyiv mayor and former heavyweight boxing champion Vitali Klitschko told Reuters nearly 2 million people were still left in the city out of a pre-war population of 3.5 million.
He said the capital had enough essential supplies to last a couple of weeks, and supply lines in and out remained open for now.
"Wrong assumptions"
Ukrainian authorities said that near the eastern town of Izyum, a psychiatric hospital had been hit. Emergency services said no one was hurt as the patients were already sheltering in the basement.
Kharkiv governor Oleh Synegubov called the attack a war crime. Reuters could not verify the report and there was no comment from Moscow.
Moscow denies it has been targeting civilians in what it calls a "special operation" to disarm and "de-Nazify" Ukraine.
Three air strikes near a kindergarten in the central city of Dnipro killed at least one person on Friday, state emergency services said.
The mayor of Lutsk said four people had been killed and six wounded in an attack on an airfield - a rare strike on a target deep in western Ukraine, far from the battlefields in the north, east and south.
In Kharkiv, hundreds of people were sheltering in metro stations deep under the streets. Mayor Ihor Terekhov said the city was under relentless bombardment and about 50 schools had been destroyed.
Nastya, a young girl lying on a makeshift bed on the floor of a train carriage, said she had been there for more than a week, unable to move around much and ill with a virus.
"I'm scared for my home, for the homes of my friends, very scared for the whole country, and scared for myself of course."
Moscow said its separatist allies in the southeast had captured the town of Volnovakha, north of Mariupol.
But Mathieu Boulegue, an expert at London's Chatham House think tank, said Moscow might not have sufficient troops to achieve its goals.
"You can't invade a country on a one-on-one ratio (of troops). Nobody has done it, which means that either something was wrong or they had very wrong assumptions moving into this war," he told Reuters.
No EU membership
Away from the battlefields, EU leaders meeting in the Palace of Versailles near Paris agreed to spend more on defence and cut reliance on Russian energy supplies by 2027. But they did not reach agreement on how far to extend their sanctions against Russia.
They also declined Ukraine's call for a speedy admission to the EU, wary of angering Moscow and of letting in a country that does not meet the bloc's criteria.
Since the invasion, Western countries have swiftly moved to isolate Russia from the global financial system.
Regarding further sanctions, French President Emmanuel Macron said: "Nothing is off the table, nothing is taboo, we'll do whatever we deem necessary to stop Russia."