Bangladesh, March 27 -- US President Donald Trump on Thursday threatened Iran with devastating attacks unless it accepts a 15-point White House peace plan, possibly through indirect talks brokered by Pakistan.

Pakistan's top diplomat confirmed those negotiations were ongoing as military activity - and rhetoric - continued to escalate.

Iran denies participating in any negotiations despite efforts by Egypt and other nations to assist, and has cemented its control over the vital Strait of Hormuz, using it as a pressure point for the world economy. Israel, meanwhile, says it will press ahead with more attacks.

Here is a look at what's known about possible talks to wind down the nearly four-week-old war.

Trump says Iran is 'begging' for a ...