A Winter Olympics overshadowed by rights concerns and Covid will officially begin in Beijing on Friday with an opening ceremony at the "Bird's Nest" stadium.

The distinctive lattice-shaped arena took centre stage at the 2008 Games -- seen as China's coming-out party to the world -- and will do so again as Beijing becomes the first city to host both a Summer and Winter Olympics.

Friday's opening ceremony starts at 8:00pm (1200 GMT) and will be attended by President Xi Jinping, under whose rule China has become a much more belligerent proposition in global affairs compared to 14 years ago.

Xi, who will announce the Games are officially open, will be joined by leaders including his Russian counterpart Vladimir Putin but the United States, Britain, Canada and Australia are among countries staging a diplomatic boycott over China's human rights record, particularly the fate of the Muslim Uyghur minority in Xinjiang.

Other countries cited the coronavirus pandemic for not sending officials.

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

Some spectators will be present at the opening ceremony 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.

World Health Organization head Tedros Adhanom Ghebreyesus and United Nations Secretary-General Antonio Guterres are among leaders of global institutions coming to the ceremony.

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

Zhang has promised a "totally innovative" show 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 there will be about 3,000 performers and themes will include "environmental protection and low carbon emission", Zhang previously told state media.

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

Covid bubble

There are other concerns around these Olympics, 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.

Striking an upbeat tone on Thursday, IOC president Thomas Bach said the Games will "change the scale of winter sports forever".

China has little tradition of winter sports but has consistently said that staging the Olympics are part of a drive to inspire 300 million people in the world's most populous nation to "engage" in ski and ice pursuits.

Bach said that goal had already been exceeded.

Concerns about Covid linger. 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 adopted the same approach to the Games, with everyone cocooned inside the bubble having daily tests and required to wear a mask at all times.

They cannot leave the "closed loop" until the Games are over.

There have been nearly 290 Covid cases in the bubble, among them an unknown number of athletes.

Germany said Thursday six members of its team had tested positive on arrival in Beijing, without saying if those concerned were athletes or support staff.