Syrian President Bashar Assad was set to begin on Thursday his first official trip to China in almost two decades, where he will ask a longtime ally for financial support to help rebuild his devastated country.

China will become one of only a handful of countries outside the Middle East that Assad has visited since the 2011 start of a war that has since killed more than half a million people, displaced millions more, and battered Syria's infrastructure and industry.

Assad also becomes the latest in a string of leaders ostracized by the West to be feted by Beijing, with Venezuelan leader Nicolas Maduro, Iran's President Ebrahim Raisi and top Russian officials all visiting this year.