(Reuters) - The U.S. should delay implementing its new tariffs for up to 90 days while trade negotiations take place, billionaire investor Bill Ackman, who endorsed Donald Trump's run for president, said in a social media post on Tuesday.

Ackman said that while he was supportive of tariffs, a 30-, 60- or 90-day pause would prevent "a major global economic disruption that would harm the most vulnerable companies and citizens of our country."

Implementing the tariffs without allowing time for agreements will do "unnecessary harm," Ackman wrote.

Ackman is among a number of high-profile executives who have expressed concerns over Trump's new tariff plan.

JPMorgan Chase CEO Jamie Dimon and BlackRock chief Larry Fink have also warned that the trade tensions could constrain the economy.

(Reporting by Niket Nishant in Bengaluru; Editing by Anil D'Silva)