TEHRAN, Iran (AP) — The blowback over the U.S. killing of a top Iranian general mounted Sunday as Iran announced it is abandoning the limits contained in the 2015 nuclear deal and Iraq's Parliament called for the expulsion of all American troops from Iraqi soil.

The twin developments, if they come to pass, could bring Iran closer to building an atomic bomb and enable the Islamic State group to stage a comeback in Iraq, making the Middle East a far more dangerous and unstable place.

Iranian state television cited a statement by President Hassan Rouhani's administration saying the country would...