WASHINGTON: Pakistan's ambassador to the United States Sherry Rehman, branded as “unhelpful” US Defence Secretary Leon Panetta's latest stab at Islamabad's failure to tackle militant safe havens.

In response to a media query about the remarks made by Leon Panetta, Sherry said “This kind of public messaging from a senior member of the US Administration is taken very seriously in Pakistan, and reduces the space for narrowing our bilateral differences at a critical time in the negotiations.”

“It adds an unhelpful twist to the process and leaves little oxygen for those of us seeking to break a stalemate,” Pakistan's envoy, Sherry Rehman, said in a statement.

Panetta, speaking in Kabul on Thursday, said the United States was reaching the limits of its patience with Pakistan because of the safe havens the country offered to insurgents fighting in neighboring Afghanistan.