NATO says it will tighten sanctions against Moscow, strengthen its forces on its eastern flank and send more military aid to Ukraine.
But the pledges fell short of Ukrainian President Volodymyr Zelenskyy's pleas for a full boycott of Russian energy products and a no-fly zone over the country.
Thousands of Ukrainians have been killed, millions have become refugees, and cities have been destroyed since Russian leader Vladimir Putin began the invasion on February 24.
"NATO has yet to show what the alliance can do to save people," Mr Zelenskyy told a NATO summit in Brussels during a special video address, adding he believed Mr Putin wanted to attack eastern NATO members as well.
Mr Zelensky insisted that Western leaders give Ukraine unlimited help against Russia, which is "without limits using its entire arsenal".
He said a tiny percentage of the warplanes and tanks controlled by NATO members could make a difference.
"Ukraine asked for 1 per cent of all your tanks. Give it to us or sell it to us," Mr Zelenskyy said, explaining the frustration of "not having clear answers to requests for help".
More troops but no no-fly zone
At the "extraordinary" NATO summit in Brussels, alliance members decided four new multinational battle groups would be established in Bulgaria, Hungary, Romania and Slovakia.
They will join the 40,000 NATO troops already deployed along the alliance's borders.
"We agreed to strengthen our deterrence and defence for the longer term," NATO secretary-general Jens Stoltenberg said after the leaders' meeting.
"We also agreed to give further support to Ukraine and to continue to impose costs on Russia."
More fighter jets will also be deployed in NATO countries, while the US and its allies will also support Ukraine with anti-ship missiles as well as extra anti-aircraft and anti-tank weapons and drones.
But the alliance rejected Ukraine's repeated calls for it to enforce a no-fly zone over the country — something that would potentially put NATO planes in direct combat with Russian aircraft.
Mr Stoltenberg also said NATO troops would not be sent into Ukraine, even in a peacekeeping capacity, as it would risk all-out war between NATO allies and Russia.
NATO said its continued support to Ukraine would include helping protect it against potential chemical, biological or nuclear attacks.
Speaking at a press conference after the meeting with NATO leaders, Mr Biden stressed that NATO and European allies were united in their efforts.
Mr Biden said he had raised the idea of removing Russia from the G20, adding that the decision was up to the group.
He also warned that China would face consequences if it chose to aid Russia's war in Ukraine.
After speaking with Chinese leader Xi Jinping last week, Mr Biden said China wanted to maintain good economic ties with the West.
"China understands that its economic future is much more closely tied to the West than it is to Russia, and so I'm hopeful that he does not get engaged," he said.
Fresh sanctions target defence companies and politicians
The US and Britain announced a fresh range of sanctions on Russia, targeting Russian defence companies, hundreds of Russian politicians and the head of the country's largest bank.
Even a socialite the UK government said is the stepdaughter of Russian Foreign Minister Sergei Lavrov has been targeted.
Polina Kovaleva reportedly owns a £4 million ($7m) property in London, with property records showing she lives in the wealthy suburb of Kensington, famous for its parks, upmarket shops and museums.
She purchased it in 2016 without a mortgage, the records show.
Another individual to be targeted is German Gref, the CEO of Russia's largest bank, Sberbank.
"Putin should be under no illusions — we are united with our allies and will keep tightening the screw on the Russian economy to help ensure he fails in Ukraine," British Foreign Secretary Liz Truss said.
UN General Assembly adopts aid resolution
Almost three-quarters of the UN General Assembly demanded aid access and civilian protection in Ukraine and criticised Russia for creating a "dire" humanitarian situation.
It is the second time the 193-member General Assembly has overwhelmingly isolated Russia since the invasion of its neighbour one month ago.
The resolution adopted on Thursday, which was drafted by Ukraine and allies, received 140 votes in favour and five votes against — Russia, Syria, North Korean, Eritrea and Belarus — while 38 countries, including China, abstained.
Ukraine and its allies had been looking to match or improve on support received for a March 2 General Assembly resolution that deplored Russia's "aggression" and demanded it withdraw its troops.
That received 141 yes votes, the same five no votes, while 35 states — including China — abstained.
US Ambassador to the United Nations, Linda Thomas-Greenfield, described the vote on Thursday as a success, telling reporters: "Today once again the world stood united … in the face of President Putin's unjustified and unprovoked invasion of Ukraine."
"Together a strong majority of UN member states made clear that Russia, Russia, bears sole responsibility for the grave humanitarian crisis and violence in Ukraine."
Russia's UN ambassador Vassily Nebenzia described the resolution adopted on Thursday as a "pseudo humanitarian draft" that took a "one-sided view of the situation.
"I think there's no point going into the details of why Russia has voted against this draft … because it was put forward exclusively to once again condemn Russia, and to apply different labels to us, as a response to those who are ready to sign to a one-sided view of the situation," he said.
The resolution demands the protection of civilians, medical personnel, aid workers, journalists, hospitals and other civilian infrastructure. It also demands an end to the siege of cities, in particular Mariupol.
ABC/Reuters
