ISLAMABAD: Prime Minister Imran Khan on Saturday formally launched the ‘Clean and Green Pakistan’ campaign in Islamabad, promising 10 billion trees countrywide in next five years.br br Speaking at a gathering, Khan said his government planted one billion trees in Khyber Pakhtunkhwa during its tenure in government in the province, and “now we will [with the grace of God] plant at least 10 billion trees in Pakistan under the campaign.