* NATO chief says incursions unintendedNATO chief apologises, Pakistani Taliban vow revenge
DEAD AND IN HELL.* Taliban vow more attacks
* Re-opening of supply route likely to be delayed
* U.S.-Pakistan tension could increase
(Adds new attack, comments from NATO/ISAF and US Embassy)
By Kamran Haider and David Brunnstrom
ISLAMABAD/BRUSSELS, Oct 4 (Reuters) - NATO's chief expressed regret on Monday for the deaths of Pakistani soldiers last week and said he hoped Pakistan's border would reopen for NATO supplies to Afghanistan as soon as possible.
Angered by repeated attacks by NATO helicopters on militant targets within its borders, Pakistan blocked one of the supply routes for NATO troops in Afghanistan after a strike killed three Pakistani soldiers in the western Kurram region.
"I expressed my regret for the incident last week in which Pakistani soldiers lost their lives," Secretary-General Anders Fogh Rasmussen said after meeting Pakistani Foreign Minister Shah Mehmood Qureshi in Brussels.
"I expressed my hope the border will be open for supplies as soon as possible."
The apology came after gunmen attacked a convoy of trucks taking goods to Western forces in Afghanistan on the outskirts of the Pakistani capital.