The US military “hasn’t even started destroying what’s left in Iran. Bridges next, then ​Electric Power Plants,” Trump wrote on social media.

His post said that Iran’s leadership “knows ​what has to be done, and has to be done, FAST!”

Trump, who ⁠has previously offered shifting timelines and objectives for the war, said in a televised ​speech on Wednesday that the war could escalate if Iran did not give in to ​Washington’s terms, with strikes on its energy and oil infrastructure possible.

Dozens of international law experts in the US signed an open letter released earlier on Thursday saying that US strikes on Iran may amount ​to war crimes.

The 1949 Geneva Conventions on humanitarian conduct in war prohibit attacks on sites ​considered essential for civilians.

The Geneva Conventions and additional protocols say that parties involved in military conflict must ‌distinguish ⁠between “civilian objects and military objectives”, and that attacks on civilian objects are forbidden.

“We are going to hit them extremely hard over the next two to three weeks. We are going to bring them back to the Stone Age, where they belong,” Trump said ​in his Wednesday address.

While ​he said Washington was ⁠nearing the completion of its goals in Iran, Trump did not lay out a timeline to end the war.

The war began ​on February 28 when the US and Israel attacked Iran. Tehran ​responded by ⁠launching its own attacks on Israel and Gulf states with US bases.

Joint US-Israeli strikes in Iran and Israeli attacks in Lebanon have killed thousands and displaced millions.

The war has also ⁠raised ​oil prices and shaken global markets. Trump’s mixed messages ​thus far have done little to ease the concerns over his country’s biggest military attacks since the 2003 ​invasion of Iraq.