US Ambassador to Pakistan Cameron Munter on Monday called the NATO attack on Mohmand Agency as a terrible tragedy, but stopped short of offering an apology on the incident in which 24 soldiers were killed. In an interview to a TV channel, he gave no indication that the US would take any action against Mansoor Ijaz, the man whose disclosure about the memo sent by former ambassador Husain Haqqani with the alleged approval of President Zardari to Admiral Mike Mullen has raised a political storm in Pakistan. This is an internal affair of Pakistan, said the US envoy. He said the US would not like to prejudge anything before the inquiry. Asked what the US would do if Pakistan did not open its airspace to NATO planes for another few weeks, the US ambassador said it was a technical question which the NATO was in a better position to answer. However, he hoped that the matter would be resolved in the near future. We are terribly sorry, he said of the tragic incident, adding that it should not have happened. We feel the same way as you do. He repeated almost the same words when reminded that an 'apology could ease the tense situation. About the state of relations between the two countries, he said they were slowly but surely improving. He said both the countries were on the same side in the war on terror.