CAIRO, July 18 (Reuters) - The delegations of the Afghan government and Taliban issued a joint statement on Sunday saying that they will meet again and that they have issued instructions to expedite their peace negotiations, Qatar"s Al Jazeera TV reported. The two delegations of negotiators, who have been in Doha since Saturday, said "the two sides committed to continue negotiations at a high level until a settlement is reached." "We will work to provide humanitarian assistance throughout Afghanistan," the statement added, according to Al Jazeera.