WASHINGTON -  With Pakistan Tehreek-i-Insaf leader Imran Khan threatening to stage a mass protest against Prime Minister Muhammed Nawaz Sharif in Islamabad, the United States has signalled it supports the elected government while upholding the right to a peaceful protest.

"We support the democratically elected Government of Pakistan. We also support the peaceful right of protest. But this is an internal matter for the Pakistani government and Pakistani authorities to speak to," State Department Spokesman John Kirby told reporters on Wednesday at the daily press briefing.

About the terrorist attack in Quetta, he said US remains committed to supporting Pakistan and the government’s efforts to end the scourge of terrorism and extremism in the country and to promote peace and stability in the region.

Kirby expressed condolences on the loss of lives in the terrorist attack, saying many of the victims were police cadets, young people who were training and learning to defend their fellow citizens.

“This is a cowardly, lethal, horrific attack. And sadly, it’s not the first time that the people of Pakistan have fallen victim to terrorism. Many soldiers have died, many civilians have died. This isn’t some theoretical exercise for the Pakistani people; it’s right there. Not in their backyard, in their front yard,” Kirby said, while condemning the attack in strong terms.

He said the United States condemns in the strongest possible terms the horrific terrorist attack on the police training centre in Quetta that claimed the lives of over 60 people. "We extend our condolences, of course, to the victims and their families, including the police cadets who were embarking on careers of public service."

Kirby said that the United States stands with the people of Pakistan and the Government of Pakistan in this very difficult hour, and "we will continue to work with our partners in Pakistan and across the region to combat the threat of terrorism".

At the same time, the spokesman said Pakistan can directly contribute to regional stability by acting against militants on its soil, who seek to attack its neighbours.

For controlling terrorism, one need to come up with a common, comprehensive and collaborative solutions, Kirby said.

"It is a regional issue. We are going to continue to work with regional countries, regional partners, to deal with this because it is a common threat to everybody. And it requires common, comprehensive, collaborative solutions," he added.