* More than 300,000 cases, in nearly every country - WHO
* "The pandemic is accelerating", WHO chief Tedros says
* WHO expects decision "very soon" on Tokyo 2020 Games
* Important for India to take "aggressive action" - WHO's Ryan
* (Adds new 2nd para on Olympics, quotes on India in final paras)
By Stephanie Nebehay and Kate Kelland
GENEVA/LONDON March 23 (Reuters) - The COVID-19 pandemic is accelerating, the World Health Organization (WHO) said on Monday, with more than 300,000 cases now recorded and infections reported from nearly every country.
Dr. Mike Ryan, the WHO's top emergencies expert, said it had advised Olympic and Japanese officials about public health risks and expected a decision "very soon" on the Tokyo 2020 Games, scheduled to open in July, amid growing calls for postponement.
While it took 67 days from the first reported case to reach the first 100,000 cases of the disease caused by the coronavirus, it took only 11 days for the second 100,000 cases, and just four days for the third 100,000 cases, WHO director-general Tedros Adhanom Ghebreyesus, said.
"We're not helpless bystanders. We can change the trajectory of this pandemic," Tedros told an online briefing for more than 300 journalists.
He called for global political commitment to change the trajectory of the pandemic, urging countries to take both defensive and attacking measures.
"Asking people to stay at home and other social distancing measures are an important way of slowing down the spread of the virus and buying time, but they are defensive measures," he said.
"To win we need to attack the virus with aggressive and targeted tactics: testing every suspect case, isolating and caring for every confirmed case and tracing and quarantining every close contact."
Tedros, citing "alarming reports" of large numbers of infections among health workers around the world, said he would urge leaders of the Group of 20 countries this week to boost production of protective gear and avoid export bans.
The Group of 20, is a forum for the world's 19 largest advanced and emerging economies, including the European Union, which Tedros said accounted for more than 80 percent of global gross domestic product (GDP). It is presided over by Saudi Arabia this year.
Ryan, asked about the Tokyo 2020 Olympics, said the WHO was feeding into deliberations by the International Olympic Committee, the Japanese government and the Tokyo 2020 Committee.
Australia and Canada have already said they are withdrawing from the 2020 Games and organisers are facing increasing pressure to postpone them for the first time in their 124-year modern history.
"I believe a decision will be made very soon," Ryan said.
He said any decision to postpone the Games would be made by Japan and the IOC, adding: "We have every confidence that the Japanese government and the IOC will not proceed with any Games should they be dangerous to athletes or spectators."
Minutes later, Switzerland's top sports body called for the Games to be postponed.
India on Monday announced a halt to domestic flights and said the majority of the country was under complete lockdown to stop the spread of coronavirus. India has reported 471 cases but health experts have warned a big jump could be imminent, which would overwhelm the underfunded and crumbling public health infrastructure.
"The future of this pandemic to a greater extent will be determined by what happens with very large, densely populated countries," Ryan said.
"So it's really, really important that India continues to take aggressive action at the public health level and at the level of society to contain, control and suppress this disease and to save lives." (Reporting by Stephanie Nebehay in Geneva and Kate Kelland in London; editing by Gareth Jones and Angus MacSwan)