The United States on Sunday night condemned as "cowardly" the suicide attack on a crowded park in Lahore, Pakistan, that killed at least 65 people.

"The United States condemns in the strongest terms today’s appalling terrorist attack in Lahore, Pakistan," National Security Council spokesman Ned Price said in a White House statement.

"We will continue to work with our partners in Pakistan and across the region, as together we will be unyielding in our efforts to root out the scourge of terrorism," added Price.