WASHINGTON: The United States State Department has publicly acknowledged that it asked Pakistan to take concrete action against the Haqqani network after last week's massive car bombing in Kabul.

Commenting on the Afghan Government's claim that Pakistan supported the group which carried out the attack, State Department's Press Office Director Elizabeth Trudeau has suggested that Islamabad continued to allow the terrorists to use its soil.

“We have consistently expressed our concerns at the highest level of the government of Pakistan about their continued tolerance for Afghan Taliban groups such as the Haqqani network operating from Pakistani soil,” the Press Office Director told a news briefing in Washington.

Elizabeth said that the Pakistan Government should not discriminate between terror groups regardless of their agenda or affiliation by undertaking concrete action against the Haqqanis.

Trudeau said that Pakistan had reiterated that it would not discriminate between terrorist groups "and we continue to call on them to live up to that commitment".

“And we did again — after this week’s attack, we have pressed the government of Pakistan to follow up on its expressed commitment not to discriminate between terror groups regardless of their agenda or their affiliation by undertaking concrete action against the Haqqanis,” Elizabeth added.

Pakistan had condemned the attack hours after it took place. “We extend our heartfelt sympathies and condolences to those who have lost their loved ones and pray for early recovery of the injured,” the Foreign Office said in a statement.

The Taliban claimed responsibility for the attack outside a building of the National Directorate for Security in Kabul that killed 64 people and injured more than 300 others.

Within hours of the attack, Afghan President Ashraf Ghani vowed "vengeance for each drop of blood spilled", while his Chief Executive Abdullah Abdullah cancelled a May 2 visit to Pakistan, citing the findings of a preliminary investigation.