Chinese President Xi Jinping has described Russia's Vladimir Putin as his "best friend" during a three-day visit to Moscow focusing on trade and relations between the two countries.
The visit comes as China-US relations have soured over a bitter trade war.
Russia had decided on a pivot to the east years ago after ties worsened with the West over the Ukraine conflict.
The two sides have signed a package of trade deals and Mr Xi also unveiled two pandas for the Moscow Zoo.
The Chinese president arrived on Wednesday and later gave a press conference where he said he had a "deep personal friendship" with his Russian counterpart.
"In the past six years, we have met nearly 30 times. Russia is the country that I have visited the most times, and President Putin is my best friend and colleague," Mr Xi said.
Mr Putin echoed the praise saying he was "pleased to say that Russian-Chinese relations have reached an unprecedented level. It is a global partnership and strategic cooperation."
Why are Beijing and Moscow 'best friends'?
The alliance between the two countries has intensified since both Moscow and Beijing feel alienated by Europe and especially the US.
Moscow's relationship with the West turned sour when Russia was put under sanctions for its involvement in the Ukraine conflict five years ago. It has also been criticised for assisting the Assad regime in Syria in 2015.
China's ties with the US have deteriorated since the Trump administration appeared to turn its back on globalisation in favour of economic national protectionism.
The two countries are currently embroiled in a trade war and tit-for-tat tariffs that intensive talks have so far failed to resolve.
With a shared sense of rejection from the West, Russia and China have hence moved closer together, both in economic and military cooperation, observers say.
The partnership has already seen an increase in trade, which grew by 25% in 2018 to hit a record $108bn (£85bn) according to the Kremlin.
China-Russia economic relationship
- China is Russia's top trading partner; Russia is China's tenth-largest trading partner
- The majority of Russian exports to China are raw materials, including energy-related products
- Most of Chinese exports to Russia are equipment, machinery, and consumer goods
- The Power of Siberia pipeline connecting Russia to China, due to be completed this year, is reportedly valued at $400bn
- Other strategic projects include energy and infrastructure projects, as well as the construction of a passenger aircraft
- China foreign direct investment into Russia hit $140m in 2017
- Chinese companies are investing heavily in Russia's Lake Baikal region, sparking a backlash from locals over the impact on the environment and fears about Chinese influence
What deals are being made?
During Xi's visit to Moscow, the two sides have promised to deepen military and economic cooperation in the future.
Among the business deals signed there is one that stands out: Russian telecoms company MTS will allow controversial Chinese tech giant Huawei to develop a 5G network in Russia.
Washington has claimed Huawei poses a national security risk and banned US firms from cooperating with the Chinese firm.
The US ban threatens to also affect Huawei's activities in Europe, Australia and Japan.
The visit was not all defence and trade talks though - there was also a bit of China's panda diplomacy at work.
At the Moscow Zoo Mr Xi unveiled two panda bears, brought to Russia in April, which will remain a long-lasting reminder of the visit.
After Mr Xi's reception in the Kremlin and a visit to the Bolshoi theatre on Wednesday, he is scheduled to head for the Saint Petersburg Economic Forum on Thursday.