You need to have negotiations over the old city. The original plan was for jerusalem to be an international city. The plan wasn't for the whole old city including the jewish quarter which is outside the 67 borders to be palestinian. Who will control the armenian quarter. That is why a declaration makes no sense. You need to negotiate for final borders and you can't just declare. This is all a waste of time.
President Rivlin meets with Pope Francis at the Vatican (Haaretz)
from the article: Netanyahu seeks to foil Palestinian declaration of statehood, again