"This incident during the Holy Month of Ramadan underscores the extremists' complete disregard for human life and the harm that they continue to inflict on the Afghan people," State Department spokesperson John Kirby said.
"Attacks like these are going to only deepen our support for the people and the government of Afghanistan and their efforts to bring security and stability to their country," he said while condemning the "horrific multipart attack".
White House Press Secretary Josh Earnest said the terror attack "is an indication of something that we have long acknowledged, which is that security situation in Afghanistan is quite difficult, particularly in the fighting season".
"What is important is the continued commitment of the United States and NATO and other international contributors to the Afghan government and the Afghan security forces," he added.
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Observing that the US and its coalition partners have good partners in the Afghan government, he said it is important that they continue to support them both militarily and economically as they seek to rebuild the institutions of that country and strengthen security forces.
"The last I heard, which is I guess a week or so ago, is that the conclusions of that review have not been presented to the President at this point," he said.
"The President will carefully consider not just the judgement of his military commanders on the ground, but also the other members of his national security as he continues to evaluate our strategy in Afghanistan," Earnest said.
The twin suicide attack on a convoy of buses carrying police cadets killed 37 people and wounded 40 others.