China and Syria announce 'strategic partnership'
The announcement was made following Assad's first official visit to China in almost two decades, in what was a rare trip abroad for the Syrian president, who until recently was an international pariah.
"Today, we will jointly announce the establishment of the China-Syria strategic partnership, which will become an important milestone in the history of bilateral relations," Xi told Assad, according to a readout from state broadcaster CCTV.
The announcement was made by the Chinese president in the southern city of Hangzhou, which is hosting the Asian games over the next two weeks.
"Faced with an international situation full of instability and uncertainty, China is willing to continue to work together with Syria, firmly support each other, promote friendly cooperation, and jointly defend international fairness and justice," said Xi.
Relations between the two nations "have withstood the test of international changes", Xi said, adding that the "friendship between the two countries has been strengthened over time".
The strategic partnership between China and Syria is one rung below what Beijing calls a "comprehensive strategic partnership".
In a swipe at the West, Xi went on to say that "China supports Syria's opposition to foreign interference, unilateral bullying... and will support Syria's reconstruction".
By offering Assad a financial lifeline, the Chinese president is also hoping to further extend Beijing's recent diplomatic success in the region.
"China is willing to strengthen cooperation with Syria through the Belt and Road Initiative, to make positive contributions to regional and world peace and development," Xi said, referring to China's wide-ranging expansion of infrastructure and other links across Asia and beyond.
Syria has slowly emerged from international isolation after the Arab League agreed in May to readmit the country after it was suspended more than decade ago.
Since 2011, Syria has faced crippling western sanctions after it cracked down on peaceful demonstrators, resulting in hundreds of thousands dying.
Many of Syria's neighbours initially backed rebels seeking to topple Assad.
Since then, Assad, with the help of Iran and Russia, has gradually retaken control over much of the country.
More recently, normalisation efforts propelled by the United Arab Emirates and Saudi Arabia have sped up dramatically, with both countries looking to bring Damascus back into regional affairs.
One of the central issues of concern for Arab League countries is Syria's highly problematic drugs trade, in particular the notorious amphetamine Captagon, which in recent years has been exported on a large scale to neighbouring countries.
Saudi Arabia has a strong desire to end Captagon inflows. Riyadh has reportedly offered Syria $4bn to compensate for the loss of earnings from the trade, though it denies this.