The UN refugee agency, UNHCR, said 3,862,797 Ukrainians had fled the country -- an increase of 41,748 from Sunday's figures.

Sharon Dijksma, the Labour mayor of the central Dutch city acknowledged that conditions in the existing centre for asylum-seekers were "disastrous" and "overcrowded" in a Twitter post.

Speaking to a group of Russian journalists via video call, Zelensky said Russia's invasion had caused the destruction of Russian-speaking cities in Ukraine, and said the damage was worse than the Russian wars in Chechnya.

Biden's point, Blinken said in Jerusalem, was that "Putin cannot be empowered to wage war, or engage in aggression against Ukraine, or anyone else".

Biden's comment that the Russian president "cannot remain in power" -- delivered in Warsaw at the close of three days of marathon diplomacy -- was termed "a horrendous gaffe" by one Republican senator.

NATO member Turkey has good relations with both Russia and Ukraine and has sought to mediate in the month-long conflict.

Biden's comments on Saturday, including a statement earlier in the day calling Putin a "butcher," were a sharp escalation of the US approach to Moscow over its invasion of Ukraine.

"It is currently impossible to estimate the extent of damage due to hostilities that do not stop in the area of the nuclear installation," the post quoted the State Nuclear Regulatory Inspectorate as saying.

The pact to be announced by U.S. President Joe Biden and the president of the EU's executive, Ursula von der Leyen, follows a day of three summits in Brussels where leaders lambasted Russia's invasion of Ukraine and offered fresh support to Kyiv.

Russia has repeatedly raised the prospect of using nuclear weapons as it struggles to overcome Ukraine's military during the month-old war that the Russian government calls a "special operation." This week, the Kremlin said such weapons would only be used in the case of an "existential threat."

"My answer is yes, depends on the G20," Biden said, when asked if Russia should be removed from the group.

Indonesia has found itself caught in a tug-of-war between Russian and Ukrainian diplomatic efforts that aim to control the public perception of the Russian invasion of Ukraine.

While Finland and Sweden's partnership with the Atlantic Alliance is nothing new, Russia's invasion of Ukraine has pushed the two militarily non-aligned nations to deepen their cooperation with NATO even further.

Indonesia is caught between welcoming Russian leader Vladimir Putin at the G20 Summit later this year and risking a boycott from other G20 members.

The United States and its Western allies are assessing whether Russia should remain within the G20, sources told Reuters on Tuesday. A G7 source, however, said it was unlikely that Indonesia, currently heading the G20, or members like India, Brazil, South Africa and China would agree to remove Russia from the group.

In a field in western France, the small purple and white flowers quivering among tender shoots of wheat are a clue that this is not conventional single-crop farmland.

"Not only G20, many organisations are trying to expel Russia....the reaction of the West is absolutely disproportional," ambassador Lyudmila Vorobyova told a news conference on Wednesday.

"We have a concept of domestic security, and it's public. You can read all the reasons for nuclear arms to be used," Peskov said. "So if it is an existential threat for our country, then it can be used in accordance with our concept."

The conflict with Russian President Vladimir Putin is redefining Biden's 14-month old presidency as he pivots from domestic woes to leading the transatlantic alliance in the most serious crisis in Europe for decades.

The likelihood that any bid to exclude Russia outright would be vetoed by others in the club - which includes China, India, Saudi Arabia and others - raised the prospect of some countries instead skipping G20 meetings this year, the sources said.

After more than a month of falling cases across much of the continent, countries such as Britain, France, Germany and Italy have all seen a dramatic resurgence of infections in recent days.

EU countries have already poured billions of euros into tax cuts and subsidies to combat surging energy bills - but with gas prices jumping to fresh records following Russia's invasion of Ukraine, countries are seeking extra options.

New cases over the previous 24 hours published on Sunday stood at 81,283, pushing a 7-day moving average to 89,002, compared with just over 60,000 average new cases one week earlier. The number of cases per 100,000 inhabitants also reached their highest value level since Feb. 18.

The UN health agency has previously said that the acute phase of the pandemic could end this year but it would depend on how quickly we meet its target to vaccinate 70 percent of the population in each country, among other factors.

Seeking to force a military withdrawal from Ukraine by Russian President Vladimir Putin, the EU - along with Western allies - has already imposed a panoply of punishing sanctions including a freezing of the assets of the Russian central bank.

"There can be no talk of surrendering weapons. We have already informed the Russian side of this," Iryna Vereshchuk told Ukrainska Pravda newspaper.

Zelensky, speaking in his daily video appeal to Ukrainians after addressing Israel's parliament by video link, said Prime Minister Naftali Bennett had been trying to act as an intermediary between Kyiv and Moscow.

"Among the responsibilities of those who wage war, everywhere in the world, is the suffering inflicted on civilians who are forced to flee their homes," said UNHCR chief Filippo Grandi.

"Le President est-il devenu fou?" (Has the president gone mad?) by Patrick Weil takes a fresh look at US president Woodrow Wilson (1913-21), who helped forge the Treaty of Versailles after World War I and tried to establish lasting peace through the creation of the League of Nations. 

The leaders of the world's two largest economies had a nearly two-hour phone call, focusing on Ukraine, where China's close ally Russia is in the fourth week of a bloody assault.