For US combat pilots in Afghanistan, there are two reasons to visit Pakistan: to help provide aid to the millions affected by devastating floods, and to improve America's image.
Torrential monsoon rains have lashed Pakistan for two weeks, triggering catastrophic flooding that the UN says has affected 13.8 million people, in a disaster eclipsing the 2004 tsunami that killed 220,000 across Asia.
Entire villages have been washed away. Parts of the country, such as the northwest Swat valley which for years was paralysed by Taliban insurgency, are cut off from the outside
world. An estimated 1,600 people have died.
The government says the international community has promised USD 92 million, but it is the presence of US military helicopters that may incite the most controversy in Pakistan,
where anti-Americanism is endemic.
The White House said that US helicopters have helped to save more than 1,000 lives in Pakistan. Washington has provided USD 35 million in aid, including 436,000 halal meals and 12 pre-fabricated bridges.
"The primary focus of our mission is to provide food to people," Major Daniel Rice, commanding officer of the US aviation fleet in Pakistan, told AFP.
Asked whether it would help remove misunderstandings about the United States in Pakistan, he said: "I certainly hope so."
"We are learning from each other every day... We are talking about each other's families as we deal together with the calamity here," Rice added.
Islamabad's alliance with Washington and the presence of nearly 150,000 US-led foreign troops fighting the Taliban in neighbouring Afghanistan has been blamed within Pakistan for its own rise in militancy.
Concerned about anti-American sentiment, the Obama administration is trying to engage more fully with Pakistan, which has long seen Washington as interested only in securing its military cooperation in fighting terrorism.