Ukrainian President Volodymyr Zelenskyy criticised the US for hesitating on supplying his country with fighter jets, saying "ping-pong" continued in discussions on who should deliver fighter planes and other defence weapons.
In an impassioned video address late Saturday Mr Zelenskyy said Ukraine could not defend itself against missiles without proper weapons and could not liberate besieged Mariupol without tanks and combat jets.
He added that he had talked to Ukrainian forces defending Mariupol today and urged Western partners to have at least "1% of their courage".
In his latest video address, the president also assailed Russian claims that Ukraine is trying to wipe out the use of the Russian language.
"You are doing everything so that our people themselves leave the Russian language, because the Russian language will now be associated only with you, with your explosions and murders, your crimes," he said.
Mr Zelenskyy angrily warned Moscow that it is sowing a deep hatred for Russia among his people, as constant artillery barrages and aerial bombings are reducing cities to rubble, killing civilians and driving others into shelters, leaving them to scrounge for food and water to survive.
Russia's invasion of Ukraine has ground into a war of attrition in many places, with the toll on civilians rising as Moscow seeks to pound cities into submission from entrenched positions.
Russian rockets struck the western Ukrainian city of Lviv on Saturday while President Joe Biden visited neighbouring Poland, serving as a reminder that Moscow is willing to strike anywhere in Ukraine despite its claim to be focusing its offensive on the country’s east.
Russia's Defence Ministry spokesman Major General Igor Konashenkov said on Sunday that Russian air-launched cruise missiles hit a fuel depot and a defence plant in Lviv on Saturday.
Early on Sunday, a chemical smell still lingered in the air as firefighters in Lviv sprayed water on a burned section of the fuel depot.
A security guard at the site, Prokopiv Yaroslav, said he saw three rockets strike and destroy two oil tanks but no one was hurt.
“The third strike threw me to the ground,” he said.
In a crowded bomb shelter under an apartment block a short way from the first blast site in Kyiv Olana Ukrainets, a 34-year-old IT professional, said she couldn’t believe she had to hide again after fleeing from the northeastern city of Kharkiv, one of the most bombarded cities of the war.
“We were on one side of the street and saw it on the other side,” she said. “We saw fire. I said to my friend, ‘What’s this?’ Then we heard the sound of an explosion and glass breaking. We tried to hide between buildings. I don’t know what the target was.”
Russia's back-to-back airstrikes shook the city that has become a haven for an estimated 200,000 people who have had to flee their hometowns. Lviv had been largely spared since the invasion began, although missiles struck an aircraft repair facility near the main airport a week ago.
Konashenkov added that another strike including sea-launched missiles, which destroyed an ammunition depot holding air defence missiles in Plesetsk just west of the Ukrainian capital of Kyiv.
A nuclear research facility in the besieged city of Kharkiv, near the Russian border, again came under fire Saturday, and Ukraine's nuclear watchdog said that because of ongoing hostilities it was impossible to assess the extent of the damage.
Kharkiv has been besieged by Russian forces since the start of the invasion and has come under repeated shelling that has hit residential buildings and critical infrastructure.
Ukrainian authorities have previously reported that Russian shelling had damaged buildings at the facility, but there had been no release of radiation.
The International Atomic Energy Agency has said the nuclear material in the facility is always subcritical and the inventory of radioactive material is very low, reducing the risks of radiation release.
Two cities on opposite ends of the country are seeing some of the worst suffering at the moment, Chernihiv in the north - strategically located on the road from the Belarusian border to the capital, Kyiv - and Mariupol in the south, a key port city on the Sea of Azov.
Both are encircled by Russian forces, but still holding out.