The number of refugees fleeing Ukraine was expected to reach 1.5 million on Sunday as Russia continued its attack 11 days after invading Ukraine and Kyiv pressed for further Western help, including more sanctions and weapons.
Moscow and Kyiv traded blame over a failed ceasefire on Saturday that would have let civilians flee Mariupol and Volnovakha, two southern cities besieged by Russian forces. Ukrainians who could escape spilled into neighbouring Poland, Romania, Slovakia and elsewhere.
Ukrainian negotiators said a third round of talks with Russia on a ceasefire would go ahead on Monday, although Moscow was less definitive.
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In a televised address on Saturday night, Ukraine's President Volodymyr Zelenskiy called on people in areas occupied by Russian troops to fight.
"We must go outside and drive this evil out of our cities," he said, vowing to rebuild his nation.
Russian President Vladimir Putin reiterated that he wanted a neutral Ukraine that had been "demilitarised" and "denazified," and likened Western sanctions "to a declaration of war," adding: "Thank God it has not come to that."
Ukraine and Western countries have decried Putin's reasons as a baseless pretext for the invasion and have imposed sweeping sanctions aimed at isolating Moscow and crippling its economy.
Ukraine's Foreign Minister Dmytro Kuleba, after meeting with US Secretary of State Antony Blinken at the Ukraine-Poland border, said he expected new sanctions and weapons for Ukraine in coming days.
The United States has said it would give Ukraine more weapons and has repeatedly warned it could escalate sanctions, with President Joe Biden seeking $10 billion in emergency funding to respond to the crisis.
Washington is working with Poland as Warsaw considers whether to provide fighter jets to Ukraine, a White House spokesperson said, adding that the United States could replenish Poland's supply of jets.
Zelenskiy asked for help securing aircraft from European allies in a video call with US lawmakers. He also called again for more lethal aid, a ban on Russian oil, a no-fly zone and an end to Visa Inc and MasterCard Inc privileges in Russia, US media reported.
Visa and Mastercard later said they would suspend credit card operations in Russia, the latest in a dramatic series of corporate pullbacks and government sanctions over the invasion.
Biden and Zelenskiy also spoke, discussing security, financial support for Ukraine and the continuation of sanctions against Russia, the Ukrainian leader wrote on Twitter.
NATO, which Ukraine wants to join, has resisted Zelenskiy's appeals to impose a no-fly zone over his country, saying it would escalate the conflict outside Ukraine.
Seeking to mediate, Israeli Prime Minister Naftali Bennett met Putin at the Kremlin on Saturday and later spoke to Zelenskiy.
"We continue dialogue," Zelenskiy tweeted after the call.
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British Prime Minister Boris Johnson issued a six-point plan to respond to the invasion ahead of meetings this week with leaders from Canada, the Netherlands and Central Europe in London.
Turkish President Tayyip Erdogan is expected to talk with Putin on Sunday. Turkey, a NATO member, shares a maritime border with Ukraine and Russia in the Black Sea.
Russia was warning the EU and NATO again to stop the "pumping of state-of-the-art weapons systems" into Kyiv, foreign ministry spokesperson Maria Zakharova said, according to RIA.
Russia's Defence Ministry said its forces were carrying out a wide-ranging offensive in Ukraine and had taken several towns and villages, Russian news agency Interfax said.
The Ukrainian armed forces said on Sunday they were conducting a number of defensive operations, including in the eastern part of the Donetsk district, in Slobozhansky, and the city of Chernihiv.
A series of blasts were heard overnight in Kharkiv, the second-largest city, Ukrainian media reported.
Ukraine's military said it had shot down 88 Russian aircraft and helicopters so far and captured some pilots. Reuters could not corroborate the claim.
The International Monetary Fund warned the conflict would have a "severe impact" on the global economy, driving up energy and grain prices. It said it would weigh Kyiv's request for $1.4 billion in emergency financing as early as this week.
'Help us if you can'
In Mariupol, which has been encircled by Russian forces and shelled for days, the situation was grim.
"We can’t collect all the bodies on the street," Deputy Mayor Sergei Orlov told CNN, saying it was impossible to count civilian deaths there.
Medical charity Medecins Sans Frontieres said it was rushing more emergency supplies to Ukraine as many hospitals were facing shortages.
Heavy shelling was heard in the background as residents of Volnovakha tried to flee.
"Help us if you can, we all want to live, we have kids, husbands, we are mothers and fathers, we are also people," said one local, Larisa. "Where shall I go? What's on me and a bag of things is all I got. That's all I have."
As night fell, more refugees crossed into Moldova.
"I'm scared," said a mother fleeing from Odessa, adding she would keep going to Poland.
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The World Health Organization said 249 civilians had been killed and 553 injured as of Thursday, when the number of refugees was 1.2 million and 160,000 people had been internally displaced.
"The human cost is likely much higher as access and security challenges make it difficult to verify the actual number of deaths and injuries," it said in a statement.
The UN refugee agency estimated the number of refugees could swell to 4 million by July.
Demonstrations were planned on Sunday in Washington and elsewhere after jailed Kremlin critic Alexei Navalny called for worldwide protests on March 6 against the war. Protests were held in Chile, Paris and Israel on Saturday.