ISLAMABAD: British Foreign Secretary William Hague voiced concern Tuesday over the seven-month impasse between Pakistan and the United States on reopening Nato supply routes into Afghanistan.

Pakistan shut its Afghan border to overland Nato supplies after US air strikes killed 24 Pakistani soldiers last November. Washington has refused to apologise formally for the deaths.

The United States said Monday it has withdrawn low-level technocrat negotiators from Pakistan after talks over getting the border open again failed.

“We look to the United States and Pakistan to work successfully together and of greater concern to us, even than those lines of communication, would be a rift between the United States and Pakistan,” the visiting British minister said.

He said he raised the issue in his meetings with Prime Minister Yousuf Raza Gilani and Foreign Minister Hina Rabbani Khar, and hoped that both sides would find a solution.

“Obviously we want this issue to be resolved and of course we raised it and discussed it today,” Hague added.

The withdrawal of US negotiators signalled further strains in relations between the nominal allies and follows criticism from US Defense Secretary Leon Panetta that saw Pakistan's army chief refuse to meet a Pentagon official.

The negotiators had been in Pakistan for about six weeks and US officials had believed they were close to a deal with Islamabad to lift the blockade.