China has called for urgent peace talks as it released its plan to end the war in Ukraine, but several Western powers rebuffed the proposals while warning against Beijing's closening ties to Moscow.
The United Nations expressed cautious optimism over the Chinese proposals, particularly over the document's call to avoid using nuclear weapons.
Russia reacted positively to Beijing's efforts and Ukrainian President Volodymyr Zelensky offered a muted response, saying Kyiv needed to "work with China" on approaches to put an end to the year-old war.
Mr Zelensky told reporters he was planning to meet with Xi Jinping after the Chinese leader's government called for the peace talks, saying it would "be important for world security."
China's 12-point paper calling for a "political settlement" of the crisis follows accusations from the West that China is considering arming Russia, a claim Beijing has dismissed as false.
Timed to coincide with the first anniversary of Russia's invasion of Ukraine, the paper urges all parties to "support Russia and Ukraine in working in the same direction and resuming direct dialogue as quickly as possible".
It also makes clear its opposition to not only the use of nuclear weapons, but the threat of deploying them, after Russian President Vladimir Putin threatened to use Moscow's atomic arsenal in the conflict.
Russia said it appreciated Beijing's efforts to settle the conflict but insisted any solution should recognise Kremlin control over four Ukrainian regions.
"We highly value the sincere desire of our Chinese friends to contribute to the settlement of the conflict in Ukraine through peaceful means," the foreign ministry said, but added any settlement must recognise "the new territorial realities".
China's document was immediately met by scepticism from Ukraine's allies, with NATO chief Jens Stoltenberg saying Beijing "doesn't have much credibility because they have not been able to condemn the illegal invasion of Ukraine".
US President Joe Biden's national security advisor said the war "could end tomorrow if Russia stopped attacking Ukraine and withdrew its forces".
"My first reaction to (the position paper) is that it could stop at point one, which is to respect the sovereignty of all nations," Jake Sullivan told CNN.
And German President Frank-Walter Steinmeier said that while "every constructive suggestion that brings us closer on the path to a just peace is highly welcome... whether global power China wants to play such a constructive role is still doubtful".
At a press conference in Beijing, Ukrainian and EU diplomats urged China to do more to press Russia to end the conflict.
Jorge Toledo, the EU ambassador to China, said Beijing has a "special responsibility" as a permanent member of the UN Security Council to uphold peace.
At the United Nations, Secretary-General Antonio Guterres's spokesman said "I think the call on the need to avoid the use of nuclear weapons is particularly important."
China has sought to position itself as a neutral party in the conflict while maintaining close ties with strategic ally Russia.
Top Chinese diplomat Wang Yi on Wednesday met with Putin and Russia's foreign minister, Sergei Lavrov, in Moscow.
A meeting readout published by Chinese state news agency Xinhua quoted Wang as saying China was willing to "deepen political trust" and "strengthen strategic coordination" with Russia.
Since Russian tanks rolled into Ukraine, China has offered Mr Putin diplomatic and financial support, but refrained from overt military involvement or sending lethal arms.
Leaders at a virtual Group of Seven summit warned countries they will face "severe costs" if they continue helping Russia evade international sanctions imposed over its invasion.
But one analyst suggested the Chinese policy paper could be laying the groundwork for further involvement by Beijing in the conflict.
"The absence of a proscription against arms transfers concerns me," former US Department of Defense official Drew Thompson wrote on Twitter.
"It is possible Beijing is getting ready to provide Russia with lethal support."
US announces $2bn in new Ukraine military aid
The United States is to send Ukraine a new military aid package worth $2bn.
US National Security Adviser Jake Sullivan made the announcement on CNN of a further $2bn in security assistance to Ukraine on the eve of the anniversary of Russia's invasion.
He did not give details of the types of armaments to be expected in the package.
The announcement comes as Ukraine marks the first anniversary of the Russian invasion today.
Mr Sullivan, who accompanied President Joe Biden on a surprise trip into Kyiv this week, said US officials were constantly deciding how "to give Ukraine the tools that it needs to win."
He noted that while in Kyiv, President Biden had delivered to Ukrainian President Volodymyr Zelensky "an announcement of more artillery, more ammunition, more HIMARS," in addition to previous pledges of US armoured vehicles and at a later date, tanks.
HIMARS are a US multiple rocket system that Ukrainian forces have used to devastating effect against invading Russian forces.
The White House said President Biden will meet virtually today with other G7 leaders and President Zelensky to mark the anniversary of the invasion.
The same Group of Seven wealthy democracies of Canada, France, Germany, Italy, Japan, UK, and US came together last year hours after President Vladimir Putin launched Russia's invasion of Ukraine, and imposed the first round of a series of sanctions.
White House press secretary, Karine Jean-Pierre, said: "The G7 has become an anchor of our strong and united response to Russia.
"The leaders will discuss how we continue supporting Ukraine and ways to increase pressure on Russia for its invasion of Ukraine a year ago."
She said the sanctions would include Russian banks, technology and defence sectors, and affect both people and companies involved in the conflict.