Iranian Foreign Minister Javad Zarif at a news conference in Vienna on Tuesday. Reuters VIENNA—Negotiations over Iran’s nuclear program on Wednesday turned to the possible extension of the talks, with senior officials saying the current round could end as early as Friday. U.S. Secretary of State John Kerry , who left Vienna on Tuesday after two days of talks with his Iranian counterpart, met with U.S. President Barack Obama and Vice President Joe Biden to discuss the negotiations and “talk about the path forward,” a senior State Department official said. Meanwhile, in Vienna, negotiators from the U.S., Iran and the European Union met for discussions that focused mainly on options for extending the negotiations, a western diplomat said. On Tuesday, both Mr. Kerry and Iranian Foreign Minister Javad Zarif signaled that negotiations would likely continue, and diplomats said the most-likely scenario was that Sunday’s deadline would be pushed back […]