Washington: The US today expressed concern over Pakistan's continued tolerance for terrorist groups like Haqqani network and said that it has raised this issue at the highest level with the authorities in Islamabad.

"We have consistently expressed our concerns at that 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," State Department Spokesman Elizabeth Trudeau said.

America's concerns were raised with Pakistan again after the dreaded terrorist attack in Kabul this week in which more than 70 people were killed.

Afghan authorities have blamed this to the Haqqani network and alleged this had the backing of the Pakistani establishment.

"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," Trudeau said in response to a question.

Pakistani authorities have reiterated their commitment that they will not discriminate against those groups, she noted.

"We continue to call on them to live up to that commitment," the State Department spokesperson said.

"I think words matter and we continue to encourage them to have their actions match those words," Trudeau said responding to Afghan allegations that Pakistanis helped the Haqqani network in this Kabul attack.

"Any attack the Haqqani group conducts is not possible without Pakistan's help and this has been repeatedly proven in the last 14 years," a presidential spokesman, Dawa Khan Meenapal, was quoted as saying by Voice of America today.