The week-long visit aims to promote London and strengthen commercial and cultural ties with Indian and Pakistani cities.
The BBC later defended the reporter's question, claiming it resulted because Punjab's chief minister Shehbaz Sharif had already described the trip as a "homecoming".
He visited Pakistan after completing his trip to India.
Earlier, in India, the Mayor met Bollywood bigwigs and addressed a couple of conferences besides visiting heritage sites.
The Mayor was received by Lahore Mayor Colonel (retd) Mubashir and Lahore Commissioner at the border.
He arrived in Lahore after a three-day visit to India.More news: Quentin Tarantino's Star Trek Movie Pitch Heads to Writers' Room
Sadiq Khan is now taking part in the first ever trade mission by a London mayor to India and Pakistan. The government, in collaboration with the Department for International Development of the United Kingdom, had already introduced far-reaching reforms in education, healthcare and skills development sectors.
PM Abbasi welcomed him and said that every Pakistani is proud of his election as Mayor of London and prays for his success.
The London mayor lauded the government, saying he is impressed with the progress made in infrastructure, technology and energy sectors.
Asked in July of this year for an update, Mr Khan said TfL expected "to be able to confirm the plan for London Overground Boxing Day services in September". "It is the heart of Pakistan and is certainly the hub of Pakistani culture", he said.
Khan was elected the first Muslim Mayor of London and was born in Tooting, south-west London.