Prime Minister Imran Khan on Tuesday thanked US President Donald Trump for hosting him at the White House with "gracious hospitality" a day earlier and assured his American counterpart that Pakistan "will do everything within its power" to facilitate the process aimed at ending Afghanistan's nearly 18-year war.

Taking to Twitter, the premier also appreciated Trump for "his understanding of Pakistan's point of view", "his wonderful way of putting our entire delegation at ease" and for showing him around the White House.

"I want to assure President Trump Pakistan will do everything within its power to facilitate the Afghan peace process," he wrote, adding that the world owed it to the people of Afghanistan to bring about peace after four decades of conflict.

Imran also said he was "surprised" by the reaction given by India to President Trump's offer to mediate between Pakistan and India to enable dialogue for resolving the Kashmir conflict.

"Generations of Kashmiris have suffered & are suffering daily and need conflict resolution," the prime minister stressed, noting that the Kashmir dispute has held the subcontinent hostage for 70 years.

His comment came hours after India's foreign ministry denied Trump had been asked by Indian Prime Minister Narendra Modi to mediate the Kashmir conflict with Pakistan.

“We have seen President Trump's remarks to the press that he is ready to mediate, if requested by India and Pakistan, on the Kashmir issue. No such request has been made by Prime Minister Modi to the US President,” said Raveesh Kumar, official spokesman of India's Ministry of External Affairs.

"It has been India's consistent position that all outstanding issues with Pakistan are discussed only bilaterally."

While speaking to the press alongside Trump at the White House, Prime Minister Imran had said that the US, being "the most powerful" country in the world, could play the most important role in bringing peace to the subcontinent.

In response, Trump said that India had also asked him to mediate.

"I was with Prime Minister [Narendra] Modi two weeks ago. We talked about the subject and he actually said, 'Would you like to be a mediator or arbitrator?'. I said where, he said Kashmir, because it has been going on for many, many years.

"I was surprised to know how long it has been going on. I think they would like to see it resolved, you [Pakistan] would like to see it resolved [...] and if I can help, I would love to become a mediator," said Trump.

In a separate tweet on Tuesday, Prime Minister Imran thanked the Pakistani-American community "for showing up in such large numbers" at the Capital One Arena in Washington DC to welcome him on his maiden visit to the US after assuming office.

Pompeo calls on PM Imran

Also on Tuesday, US Secretary of State Mike Pompeo called on Prime Minister Imran at Pakistan House in Washington DC.

Foreign Minister Shah Mehmood Qureshi, Foreign Secretary Sohail Mehmood and Ambassador of Pakistan to US Dr Asad Majeed Khan were present during the meeting, the Government of Pakistan said in a tweet.