WASHINGTON -- US President Donald Trump will respond to a proposal for a two-week extension to the deadline for US strikes on Iran, delivered by Pakistan's Prime Minister Shehbaz Sharif, White House Press Secretary Karoline Leavitt said Tuesday.

Trump has been made aware of the proposal, "and a response will come," Leavitt told online US media outlet Axios, hours before the 8 p.m. Eastern Time deadline Trump set for Iran to make a deal and reopen the Strait of Hormuz.

"To allow diplomacy to run its course, I earnestly request President Trump to extend the deadline for two weeks. Pakistan, in all sincerity, requests the Iranian brothers to open Strait of Hormuz for a corresponding period of two weeks as a goodwill gesture," Sharif wrote Tuesday on X.

On Tuesday morning, Trump threatened that Iran's "whole civilization will die tonight" if a deal is not reached.

"A whole civilization will die tonight, never to be brought back again. I don't want that to happen, but it probably will," Trump wrote on Truth Social.

On Monday, Trump said that his administration is planning to strike and destroy bridges and power plants across Iran by midnight Tuesday.

"We have a plan, because of the power of our military, where every bridge in Iran will be decimated by 12 o'clock tomorrow night, where every power plant in Iran will be out of business, burning, exploding and never to be used again," Trump told reporters at the White House.

Trump and the White House dismissed concerns that targeting such infrastructure could constitute a war crime.