President Xi Jinping underscored Beijing's close ties with Moscow and cooperation on Syria ahead of the Sochi Olympics opening ceremony Friday, as China's first leader to attend a major overseas sports event.

Xi also chose the country as his first foreign destination after taking office in March 2013, and his three-day visit this week is his first trip abroad in 2014.

"China and Russia are good neighbours, good partners and good friends," Xi was paraphrased as saying while meeting his Russian counterpart Vladimir Putin at the Black Sea resort on Thursday, according to the Chinese foreign ministry's website.

"China and Russia will continue to cooperate closely on major international and regional issues," in particular a naval escort of Syria's chemical weapons, Xi was further cited as saying.

He also stressed boosting the two countries' energy ties, while Putin noted that past militarism of China's longtime rival Japan could not be forgotten, echoing recent criticisms by Beijing, the foreign ministry said.

Beijing is locked in an escalating territorial dispute with Tokyo and has increasingly attacked its 20th century imperial aggression.

China and Russia have supported an international deal for Syria to eliminate its chemical weapons cache, and as veto-wielding members of the United Nations Security Council, they have sided with one another against Western powers in the Middle Eastern country's protracted conflict.

State-run media have highlighted Xi's trip as a sign of strong ties between the two countries, contrasting it with Western heads of state who opted to skip the Winter Games.

"While most world leaders, notably those from the US, the UK, France and Germany, will not go to Sochi amid a spectre of censure, Xi's presence makes close Sino-Russian ties even more prominent," the Global Times said in an editorial on Friday.

US President Barack Obama and a host of key EU leaders will be absent from the opening ceremony, in what is seen by some as a snub to Russia after it passed a widely-condemned law banning the spread of gay propaganda to minors.

Xi's attendance "constitutes an unconventional protocol in China's diplomatic endeavours," the editorial said, adding that "the bilateral ties are enjoying the best time ever in history".

"China and Russia will maintain close contact and coordination on major international and regional issues, such as the Syria crisis," the Xinhua state news agency said earlier this week.

Xi's visit "is another case in point that the two sides have each other's support over issues of major concern", it said.