ISLAMABAD // Pakistan's political leaders have described Mr Holbrooke's death as "a great loss".
"Pakistan has been deprived of a best friend," said Asif Ali Zardari, the president, in a statement.
Mr Holbrooke had instrumental in improving relations with Pakistan since 2009.
He worked tirelessly to persuade sceptical officials in Pakistan that the US was seeking a long term relationship, rather than a "transactional" one that would end with the departure of US forces from Afghanistan.
His lobbying of the US Congress helped secure in November 2009 a five-year, $7.5 billion civilian aid package.
That led to the establishment of regular "strategic dialogue" early this year.