Talks on a ceasefire in the Gaza Strip are continuing at the working-group level in Cairo, despite Israel and Hezbollah’s heavy exchange of fire, a senior US official said on Monday. “There continues to be progress, and our team on the ground continues to describe the talks as constructive,” White House national security spokesperson John Kirby said. Kirby said Brett McGurk, US President Joe Biden’s top Middle East advisor, stayed on in the Egyptian capital for another day to help “kick off” the lower-level consultations. “All parties will be represented, including Hamas, in those working grou…