"There's an international responsibility to cooperate to bring the perpetrators to justice and that Pakistan has a special responsibility to do so transparently and urgently," State Department spokesman Mark Toner told reporters at his daily news conference.
He was responding to queries on a statement of Tahawwur Hussain Rana, Pakistani-Canadian accused in the terror attack case, in court that he provided "material support" to the terrorists at the behest of the Pakistan government and its spy agency ISI and not the terror group Lashkar-e-Taiba.
State Department spokesperson, however, refused to make any comment on this statement by Rana, arguing this is sub-judice.
"I'm not going to talk about what this individual has said in pre-trial documents or in pre-trial hearings, because it is a legal process that's moving forward," he said.
"This individual is in a trial right, or the trial hasn't begun, it's a pretrial period, so I'm not going to talk about his comments. That would be irresponsible and I'm not going to do it," Toner said.
According to court document, Rana in his defence had said his "alleged illegal acts of providing material support to terrorists -- were done at the behest of the Pakistani government and the ISI, not the Lashkar terrorist organisation." His trial is set to begin on May 16.
However, Toner, in response to another question said the US is working with Pakistan on counter-terrorism measure.
"If you're talking about broader counter-terrorism cooperation with Pakistan, certainly that's ongoing and we are very candid in sharing our views and sharing information with Pakistan about terrorist threats, and we believe that that cooperation continues to be good."