India, Jan. 3 -- US President Donald Trump and a top Iranian security official exchanged duelling threats on Friday as widening economic protests swept across parts of the Islamic Republic, further escalating tensions between the countries after America bombed Iranian nuclear sites in June.

Trump initially wrote on his Truth Social platform, warning Iran that if it "violently kills peaceful protesters," the United States "will come to their rescue." At least seven people have been killed so far in violence surrounding demonstrations. "We are locked and loaded and ready to go," Trump wrote, without elaborating.

Shortly after, Ali Larijani, a former Parliament Speaker who serves as the secretary of Iran's Supreme National Security Council...