The leaders are attending a two-day summit of the Shanghai Cooperation Organisation, or SCO, which also includes India, Pakistan and several ex-Soviet Central Asian nations.
Welcoming Xi at the start of the talks in Kazakhstan's capital Astana, Putin said the Chinese leader's visit to Russia later this year would be a "major event."
Xi in turn hailed the "strategic" China-Russia ties, saying that "our cooperation and mutual support have a great global significance."
Iran, Afghanistan, Mongolia and Belarus have an observer status in the group.