The United States’ refusal to apologize for a 2011 military strike that killed two dozen Pakistani troops continues to hold up any final agreement to open transit routes into Afghanistan, a senior Pakistani diplomat tells CNN.

The official described the talks as being in hiatus after U.S. negotiators left the country this week following nearly two months of talks over reopening land routes from Pakistan into Afghanistan that have been used to carry supplies for the war.

The official spoke on background because of the sensitivity of the issue…

The Pakistani official said the demand was not that President Obama himself necessarily apologize; a gesture from the administration of an apology by Secretary of State Hillary Clinton would be acceptable. Senior U.S. officials have expressed regret for the killings and have issued condolences.