NEW YORK - Former president Asif Ali Zardari has told the United States that Pakistan was committed to fight terrorism as he voiced concern over the deterioration of Islamabad-Washington relations.

"We are fighting for our lives," Zardari, who is also co-chairman of the Pakistan People's Party (PPP), said, referring to mass-casualty attacks by the Taliban and Al-Qaeda, most recently in Lahore, in a letter published in The New York Times on Saturday.

"If there are factions in Congress that don’t believe that we are committed to fighting terrorists, they should come to Pakistan and bear witness to our solidarity and resolve," the former president said, while responding to a recent Times' editorial that blamed Pakistan for all the troubles in neighbouring Afghanistan.

"The struggle between Pakistan and the United States over the purchase of F-16 fighter jets demonstrates how far apart our two countries have grown," Zardari said. "What was once a strong partnership allied against threats to the region from Russia and non-state actors is sadly frayed.

"The threats, however, remain."

Zardari added, "Despite our common security interests and a deep democratic kinship, there is ambiguity toward the bilateral relationship from officials in both countries. In Congress, there is outright opposition to supporting the fighter deal.

"In the coming week, State Department officials will be in Pakistan for meetings with our government. I hope that they will take this opportunity to assure us that they remain committed to supporting our security needs."