Xi Jinping and Vladimir Putin applauded on Monday the solidity of their alliance as the Chinese leader headed to Moscow for a summit with the internationally isolated Russian president.
Xi described his trip as a "journey of friendship, cooperation and peace", though China has been criticised by Western nations for what they consider tacit backing and diplomatic cover for Russia's war in Ukraine.
"I look forward to working with President Putin to jointly adopt a new vision" for relations, Xi wrote in a signed article in the newspaper Russian Gazette that was also carried by Chinese state news agency Xinhua.
China has sought to portray itself as a neutral party in the Ukraine war, and its foreign ministry said last week that Beijing would "play a constructive role in promoting peace talks" between Kyiv and Moscow.
Beijing in February issued a 12-point position paper calling for dialogue and respect for all countries' territorial sovereignty.
Putin has welcomed Beijing's statements on Ukraine as being indicative of a willingness to play a "constructive role" in ending the conflict, while saying Chinese-Russian relations were "at the highest point".
Kyiv on Monday reiterated calls for Russia to withdraw its forces from Ukraine ahead of Xi's arrival.
"The formula for the successful implementation of China's 'Peace Plan'. The first and foremost point is the surrender or withdrawal of Russian occupation forces from (Ukrainian territory) in accordance with international law and the UN Charter," the secretary of Ukraine's National Security and Defence Council, Oleksiy Danilov, wrote on Twitter.
Xi's trip serves to bolster an isolated Putin, who in a defiant move on Sunday went to the Ukrainian city of Mariupol -- his first visit to territory captured from Kyiv since Moscow's invasion in February 2022.
Xi's visit also comes just days after the International Criminal Court (ICC) issued an arrest warrant for Putin on the war crime accusation of unlawfully deporting Ukrainian children.
Beijing said on Monday the ICC should avoid what it called "politicisation and double standards", and respect the principle of immunity for heads of state.
The court should "uphold an objective and impartial stance" and "respect the immunity of heads of state from jurisdiction under international law", foreign ministry spokesperson Wang Wenbin told a regular briefing.
The solution to the Ukraine conflict, he added, remained "dialogue and negotiation".
Neither China nor Russia are signatories to the Rome Statute, which established the ICC.
Xi, who broke longstanding precedent to begin a third term as president this month, has referred to Putin as an "old friend".
Beijing and Moscow have drawn closer in recent years under a "no limits" partnership that has served as a diplomatic bulwark against the West.
China has lambasted what it sees as a US-led campaign of pressure against Russia as Moscow's war in Ukraine drags on, instead calling for what it calls "impartial" mediation of the conflict.
"No single country should dictate the international order," Xi wrote in his Russian media article Monday.
"China has all along upheld an objective and impartial position based on the merits of the issue, and actively promoted peace talks," he added.
Beijing's stance has drawn criticism from Western nations, which say China is providing diplomatic cover for Moscow's war.
They argue that China's proposals are heavy on grand principles but light on practical solutions.
The United States last week said China's proposals would simply consolidate "Russian conquest" and allow the Kremlin to prepare a fresh offensive.
"We don't support calls for a ceasefire right now," National Security Council spokesman John Kirby said Friday.
"We certainly don't support calls for a ceasefire that would be called for by the PRC in a meeting in Moscow that would simply benefit Russia," he said, referring to the People's Republic of China, the country's official name.
Washington has also accused Beijing of mulling arms exports to Moscow -- claims China has vociferously denied.
Analysts say Xi's moves are unlikely to yield a rapprochement in the Ukraine war.
Nevertheless, his trip will be closely watched in Western capitals.
The Wall Street Journal has reported that Xi could also be planning his first call with Ukrainian President Volodymyr Zelensky since the war began.
Zelensky has said he would welcome talks with his Chinese counterpart.
Xi and Putin are set to have an "informal" one-on-one meeting and dinner on Monday before negotiations on Tuesday, Putin's top foreign policy adviser Yuri Ushakov told Russian news agencies.
They will also sign an accord "on strengthening (the two countries') comprehensive partnership and strategic relations entering a new era", the Kremlin has said, as well as a joint declaration on Russian-Chinese economic cooperation until 2030.