People from Donbass rest in an accommodation site for refugees in Rostov Region, Russia, on Saturday. — XINHUA/VNA Photo

KYIV — Moscow ordered its troops to advance in Ukraine "from all directions" while the West responded late on Saturday with sanctions that sought to cripple Russia's banking sector.

Ukrainian officials said 198 civilians, including three children, had been killed since on Thursday, and warned Russian saboteurs were active in Kyiv where explosions forced residents to flee underground.

Moscow said it fired cruise missiles at military targets, continuing the offensive after accusing Ukraine of having "rejected" talks.

Ukraine's army said it held back an assault on the capital – but was fighting Russian "sabotage groups" that had infiltrated the city.

"We will fight until we have liberated our country," Ukrainian President Volodymyr Zelensky said in a video message.

He earlier said Ukraine had "derailed" Moscow's plan to overthrow him and urged Russians to pressure President Vladimir Putin into stopping the conflict.

The United Kingdom, Germany, Italy, Canada, the United States, France and the European Commission agreed to impose new "tough financial sanctions" on Russia, including disconnecting some of its banks from the SWIFT system, German government spokesman Steffen Hebenstreit told reporters on Saturday.

"All Russian banks, who are already under international sanctions, as well as other Russian banks if necessary, will be disconnected from SWIFT," he said.

Russian President Vladimir Putin said in a televised address on February 24 that in response to a request by the heads of the Donbass republics he had made a decision to carry out a special military operation in order to protect people "who have been suffering from abuse and genocide by the Kiev regime for eight years." The Russian leader stressed that Moscow had no plans of occupying Ukrainian territories. Its objectives are demilitarisation and denasification of the country.

After the announcement, the United States, the European Union, the United Kingdom and some other countries announced they were imposing sanctions on Russian officials and individuals.

The European Union is set to disconnect several Russian banks from the international SWIFT system, European Commission President Ursula von der Leyen said on Saturday.

"We commit to ensuring that a certain number of Russian banks are removed from SWIFT," she said.

In her words, the move would efficiently block Russian imports and exports.

The United States, the United Kingdom, Germany, Italy, Canada, France and the European Commission have agreed to disconnect several Russian banks from the SWIFT international interbank system, the countries said in a joint statement.

"As Russian forces unleash their assault on Kyiv and other Ukrainian cities, we are resolved to continue imposing costs on Russia that will further isolate Russia from the international financial system and our economies. We will implement these measures within the coming days," the statement says.

"Specifically, we commit to undertake the following measures: first, we commit to ensuring that selected Russian banks are removed from the SWIFT messaging system. This will ensure that these banks are disconnected from the international financial system and harm their ability to operate globally," the document says.

Meanwhile, the Pentagon estimates that roughly half of the more than 150,000-strong force built up by Moscow on Ukraine's borders in recent months is now inside the country.

But there had been a "lack of momentum over the last 24 hours", and the Russian military had still not gained air superiority over the country, a US official said.

Tens of thousands more are estimated to be displaced within Ukraine.

In neighbouring Romania, Olga, 36, was among hundreds to have crossed the Danube river with her three young children to safety.

"My husband came with us as far as the border, before returning to Kyiv to fight," she said.

Thousands have made their way to Poland by train.

"Attacks were everywhere," said Diana, 37, who fled the Ukrainian capital.

"My mother is still in Kyiv."

As air raid sirens rang out in the capital, residents sought sanctuary in subway stations and cellars, while Zelensky announced a baby girl had been born on the metro.

The city said anyone outside after 5:00pm (1500 GMT) would be considered "members of the enemy's sabotage and reconnaissance groups".

The curfew will last until 8:00am on Monday.

Yulia Snitko, a pregnant 32-year-old, said she had sheltered in the basement of her Kyiv apartment block on Friday night, fearing premature labour.

"It was more than one hour of huge explosions. I was trembling," she said.

Participants of the peaceful manifestation 'in solidarity with Ukraine' at Freedom Square in Poznan, Poland, on Saturday. The demonstration is an expression of protest against Russia's military actions and of solidarity with the fighting Ukrainian nation. — PAP/VNA Photo

Thousands around the world demonstrated their solidarity with Ukraine on Saturday.

Washington announced $350 million of new military assistance.

Berlin said it would send Kyiv 1,000 anti-tank weapons and 500 Stinger missiles, in a major U-turn from its longstanding policy of not exporting weapons to war zones.

Paris said it would deliver more arms to Ukraine.

The European Union member states will close their airspace for Russian planes, the ARD television reported on Saturday citing own sources.

The channel did not specify when the ban will be imposed. The following countries have already closed their airspace for Russian aircraft: the United Kingdom, Bulgaria, Czech Republic, Poland, Romania, Slovenia, Latvia, Lilthuania and Estonia.

Earlier, Germany’s largest air carrier Lufthansa said it was cancelling flights to Russia and will refrain from using its airspace for transit during the next seven-day period.

The UN Security Council will convene on Sunday afternoon to vote on a resolution calling for a special session of the General Assembly over the Russian invasion of Ukraine, diplomats have said.

NATO said it will deploy its 40,000-strong rapid response force to Eastern Europe for the first time, but stressed it will not send forces to Ukraine.

On the ground on Saturday, AFP reporters in Kyiv heard occasional blasts of what soldiers said were artillery and Grad missiles being fired, with loud explosions reported.

Emergency services said a high-rise apartment block was hit on Saturday night, with a hole five floors high blown out of the building.

Kyiv Mayor Vitali Klitschko said the building had been hit by a missile, and that Russian forces were battling to advance from the northwest and west of the city.

An oil depot near Vasylkiv town (18 miles southwest of Kyiv) was targeted overnight causing a huge fire, according to the Special Communications Service on Sunday, which added a gas pipeline in eastern Kharkiv had also been hit.  — AFP/TASS