Billionaire hedge fund manager Ray Dalio said the White House’s deliberation on a block on U.S. investments in China made him wonder if bigger moves are on the way.

Dalio, founder of the world’s largest hedge fund, said that President Donald Trump could use special emergency powers like the freezing of Japanese assets and embargoing of oil to Japan in the 1940s.

“Regarding the capital and currency wars, the ability of the US president to unilaterally cut off capital flows to China and also freeze payments on the debts owed to China and also use sanctions to inhibit non-American financial transactions with China must be considered as possibilities,” Dalio, the co-chairman of Bridgewater Associates, said.

“That’s why the proposed step of limiting American portfolio investments in China makes me both think about the implications of this step and wonder if it is an inching toward bigger moves,” he added.