Russian President Vladimir Putin on Sunday welcomed China's willingness to play a "constructive role" in ending the war in Ukraine, saying relations between Moscow and Beijing were "at the highest point."

In an article released on the eve of a visit to Moscow by his Chinese counterpart Xi Jinping, Putin said Russia had high hopes for the visit by his "good old friend."

The three-day trip, which begins Monday, is the Chinese leader's first to Russia since Putin launched his invasion of Ukraine in February last year.

China has publicly remained neutral over the conflict while criticizing Western sanctions against Russia and reaffirming its close ties with Moscow.

Beijing said Xi is hoping to deliver a breakthrough on Ukraine as it seeks to position itself as a peacemaker.

What else did Putin say?

The Russian president said the quality of ties between Moscow and Beijing is "higher than the political and military unions of the Cold War era."

"We have no doubt that they [the talks] will give a new powerful impetus to the whole bilateral cooperation," he wrote in an article for a Chinese newspaper.

'Events taking place in Ukraine'

"We are grateful for the balanced line of (China) in connection with the events taking place in Ukraine, for understanding their background and true causes," Putin added.

The Russian president said he was grateful to Beijing for its "balanced" stance on events in Ukraine and its understanding of the conflict's backstory and the "real reasons" behind it.

"Russia is open to a settlement of the Ukrainian crisis by political-diplomatic means," Putin assured in the article.

However, he insisted that Kyiv recognizes the "new geopolitical realities" — namely Russia's annexation last year of four Ukrainian regions, as well as the Crimean peninsula back in 2014.

"Unfortunately, ultimatums to Russia show that (their authors) are far from these realities and have no interest in seeking a solution," he added.

Xi responds in Russian newspaper article

The Chinese president on Monday that Beijing's proposal on how to reach a settlement in Ukraine reflects global views and serves to neutralize the consequences of the crisis, but acknowledged the solutions may not be easy.

"Complex problems do not have simple solutions," Xi wrote in an article in Rossiiskaya Gazeta, a daily published by the Russian government.

Beijing last month published a 12-point paper calling for dialogue and a settlement in Ukraine, but it lacked concrete proposals for how the year-long war might end.

Announcing Xi's trip Friday, Chinese foreign ministry spokesman Wang Wenbin said Beijing would "play a constructive role in promoting peace talks."

Xi was last week reappointed for a third term and is pushing for a greater role for China on the global stage.

He played a crucial role in mediating a surprise rapprochement between Middle Eastern rivals Iran and Saudi Arabia that was announced this month.

Ukraine cautiously welcomed the Chinese settlement paper, but Kyiv has insisted that any settlement would require Russia to withdraw from all the territory it has seized including Crimea.

Washington doubts peace plan

The United States, however, reacted with extreme skepticism, given China's refusal to condemn Russia's invasion.

Washington said a cease-fire now would lock in Russian territorial gains and give Putin's army more time to regroup.

US officials are concerned China might provide Russia with weapons, which Beijing has denied.