Despite western pressure, China has joined Russia to oppose further Nato expansion.
During Vladimir Putin's visit to Beijing for the Winter Olympics, Moscow and Beijing issued a statement outlining their agreement on a variety of issues.
Mr Putin accuses the NATO defence alliance of being used by Western powers to undermine Russia.
About 100,000 Russian troops remain along Ukraine's border, which is a former Soviet republic. Meanwhile, President Vladimir Putin denies any plan to invade Ukraine.
Putin has declared that the Russians and Ukrainians are "one nation", demanding that Ukraine be barred from joining Nato. Despite the lengthy joint statement not directly addressing Ukraine, the two countries accused Nato of adhering to Cold War beliefs.
Kremlin officials described the talks, which took place ahead of the opening ceremony, as "very warm". It was the first time the leaders have met since the pandemic began.
According to the statement "Friendship between [Russia and China] has no limits, there are no 'forbidden' areas of cooperation."
According to the two countries, they are extremely concerned about the Aukus security pact between the US, UK, and Australia.
Aukus, announced last year, will see Australia build nuclear-powered submarines as part of its efforts to boost security in the Asia-Pacific region. This is viewed primarily as a response to China, which has been accused of raising tensions in disputed areas such as the South China sea.
At the same time, Russia declared support for Beijing's One China policy, which says self-ruled Taiwan is a breakaway province that will one day be returned to China.
The Taiwanese, however, see themselves as independent states, with constitutional governments and democratically elected leaders.
The star of the Beijing winter games is Russian President Vladimir Putin. However, the most significant aspect of this visit is the increased cooperation and shared worldview that Presidents Xi and Putin wish to exhibit.
In spite of the fact that Ukraine was not specifically mentioned, it was clearly implied when both countries said they oppose NATO expansion.
For China, this represents a delicate balance. Xi's standing could suffer if Russia invades or attacks Ukraine as Beijing has economic and political ties with Ukraine.
US accused Russia of fabricating an attack on Ukraine so that it could justify an invasion. Russia denied it had such plans, and the US provided no evidence to back up its claim
As part of its support for Nato allies, the US announced earlier it would send more troops to eastern Europe. Russia branded the move "destructive" and showed why it was concerned about Nato's eastward expansion.