Pakistani security sources said new U.S.-Iran talks are likely to take place before Friday in Islamabad. They cited C-17 transport planes landing at Nur Khan Airbase near the capital, road closures leading to the Red Zone, and restrictions on hotel bookings as signs of heightened preparations. Serena Hotel, which hosted the first U.S.-Iran talks on April 11, was again identified in connection with the expected diplomatic activity. The new details add to earlier reports that Pakistan had already tightened security in Islamabad, including transport restrictions, while no official timetable had been publicly announced.