The opening ceremony of the Beijing Winter Olympics began on Friday as China attempted to turn the page on a troubled build-up overshadowed by human rights concerns and Covid.

The lattice-shaped "Bird's Nest" stadium took centre stage, just as it did at the 2008 Games -- seen as China's coming-out party on the world stage -- as Beijing becomes the first city to host both a Summer and Winter Olympics.

The opening ceremony was attended by President Xi Jinping, under whose rule China has adopted a more muscular attitude internationally compared to 14 years ago.

Xi, who will declare the Games officially open, will be joined by more than 20 world leaders including Russian counterpart Vladimir Putin, the two presidents having met earlier in the day.

China and Russia have both seen ties with Washington deteriorate markedly, and with tensions rising in Europe over Russia's troop build-up on the Ukrainian border, Putin hailed the "truly unprecedented nature" of relations with his hosts.

The United States, Britain, Canada and Australia are among countries staging a diplomatic boycott of the Games over China's rights record, particularly the fate of the Muslim Uyghur minority in Xinjiang.

Their athletes will still compete at the Games, which run until February 20 and are taking place inside a vast "closed loop" designed to thwart the virus.

Some spectators will be present at the opening ceremony at the 90,000-capacity "Bird's Nest" but it is unclear how many and, like sports events at the Games, tickets were not sold to the general public because of the pandemic.

The show is the mastermind of acclaimed Chinese film director Zhang Yimou, who was behind the 2008 extravaganza.

Zhang has promised a "totally innovative" ceremony but conceded that the pandemic and freezing weather will limit its scale compared to the Summer Games, when 15,000 performers took part in a lavish gala featuring opera singers, acrobats and drummers.

This time about 3,000 performers will take part and themes will include "environmental protection and low carbon emission".

'Appalling' 

But China's assertion that these will be a "green Games" has been challenged by some experts because they are taking place in one of the driest places in the country and on almost entirely man-made snow. 

There are other concerns, including warnings from some Western nations about surveillance of their athletes and what will happen to them if they make anti-China comments or other displays of protest against local authorities.

Gus Kenworthy, a British freestyle skier, said he would not be silenced and called China "not well suited" to be hosts.

"In my opinion I don't think any country should be allowed to host the Games if they have appalling human rights stances," he told the BBC.

On Thursday, about 500 Tibetans marched outside the International Olympic Committee headquarters in Lausanne, Switzerland. Smaller demonstrations took place in Los Angeles and San Francisco.

Covid also looms large. The nearly 3,000 athletes and tens of thousands of support staff, volunteers and media have been cut off from Beijing's general population.

China, where the virus emerged in late 2019, has pursued a no-nonsense zero-Covid policy nationwide and has adopted the same approach to the Games, with everyone inside the bubble tested daily and required to wear a mask at all times.

There have been more than 300 Covid cases in the bubble, among them an unknown number of athletes. 

'In our hearts' 

Unlike the huge celebrations and outpouring of national pride that greeted the 2008 opening ceremony, enthusiasm for these Games has been noticeably more sober this time among the locals.

Covid restrictions mean that most will watch the show from home.

Those lucky enough to be there in person were told to wear a mask at all times and sit several seats apart.

Speaking on the streets of the capital, Yin Rui, 31, said she was eager to get settled in front of her television.

"Even if they are at home people will cheer for the Olympics," she told AFP, adding that "enthusiasm in everyone's hearts remain" for the Games -- even though they will take place behind high fences and with the public mostly shut out.

Away from the ceremony, the figure skating began with strongly fancied American Nathan Chen firing a warning to Japanese reigning champion Yuzuru Hanyu by producing a personal best score in the men's single short programme of the team competition.

The two will vie for gold in the eagerly awaited men's single event beginning on Tuesday.