Iran's president has defended a memorandum of understanding with the U.S. as the best way to end a stalled conflict. But Iran's new security chief took a more defiant stance Sunday and warned neighboring countries against joining new U.S. sanctions and threatened retaliation. The U.S. treasury secretary on Monday is expected to announce the new economic measures against Tehran. Also Monday, Pakistan’s army chief plans to travel to Tehran as mediators try to revive talks. Meanwhile in Gaza, health workers say an Israeli strike killed a 4-year-old child. And violence continues in the occupied West Bank.