U.S. Secretary of State John Kerry speaks during a news conference in Vienna on Tuesday. Reuters VIENNA—After two days of talks over Iran’s nuclear program, U.S. Secretary of State John Kerry and Iranian Foreign Minister Javad Zarif said Tuesday there had been progress but that significant differences remain. In comments that appear to significantly raise the chance that Washington will agree to extend talks beyond July 20, Mr. Kerry said he sees a way for the negotiations to advance and that there is much work still to do. Mr. Kerry said the U.S. is committed to a “diplomatic course” in the negotiations over Iran’s nuclear program. “I have said—and I repeat—there has been tangible progress on key issues,” Mr. Kerry said. “However, there are also very real gaps on other key issues.” The U.S. has been calling for a significant reduction in Iran’s nuclear capabilities in return for a […]