Aimed at cooling political instability in the South Asian nation, the talks had started late last year ahead of the judgment in the land corruption case against the 72-year-old former cricket star-turned-politician, Reuters reported.
The graft case is the largest that Khan faces in terms of financial impropriety. It involves land given by a real estate tycoon to a welfare institution set up by Khan and his wife in return for illegal favors.
"Khan has called off negotiations," the party chairman, Gohar Khan, told reporters in comments telecast live by local Geo News TV after he said he met the former premier in jail.
He said Imran Khan conveyed his decision after the expiry of a seven-day deadline he had given to the government to respond to demands he had given last week.
Khan's Pakistan Tehreek-e-Insaf (PTI) party mainly demands the setting up of two judicial commissions to probe the events that led to his arrest in August 2023, and the violent protest rallies, including one on May 9, 2023, when his supporters rampaged through military offices and installations.
Khan's removal from office in 2022 stoked the instability, which has worsened with his party leading violent protests to urge his release, and threatens an economic recovery under a $7 billion IMF bailout.