Hong Kong's chief executive said Tuesday that "there is no way that one could prove" that human rights organizations such as Amnesty International as well as individuals leaving the city are doing so on account of the National Security Law.

On Monday, Amnesty announced that it will close its two offices in Hong Kong before the end of the year, "driven by Hong Kong's national security law" imposed by Beijing in 2020.

"Different associations and various individuals have explained or justified their actions on the basis of the National Security Law, but there is no way that one could prove that this is exactly the reason for their taking of such a decision," Carrie Lam said before the weekly Executive Council meeting in response to a reporter asking for comment on Amnesty's decision.