That is patently false. The CDC head was briefed by the Chinese "around New Year's Day" 2020 (https://www.nytimes.com/2020/03/28/us/testing-coronavirus-pa...). By Jan 7, 2020 the CDC had already setup a task force to deal with the COVID threat. I certainly don't want to defend the Chinese government. I'm sure there are a lot of things they did wrong (on top of all the horrendous human rights abuses they commit on a daily basis), but the whole narrative of blaming China for COVID seems like an obvious ploy to shit blame away from our own incompetent response. The fact of the matter is that we saw this coming in slow motion and comprehensively failed to respond in a way that could have prevented this human tragedy.
Even if they knew, if they had themselves been moral and decided to stop all travel, it would've been fair to say we are all responsible. They did not do that. Sure all the countries are at fault too definitely (me, as an Indian, included) but doesnt take away the fact that Chinese authorities downplayed this and led to the spread. No matter how you put it and the moment it had spread world over, stopped flights to China to stop spread.
Sorry, all governments are to blame here, for sure (these deaths cant be justified) but China and to a large extent WHO are in the blame here too. Majorly.