London, Dec 16 (IANS): Hassan Nawaz, the son of ailing former Pakistan Prime Minister Nawaz Sharif, has said that it would be difficult for his father to fly to the US for further treatment until his platelet count stabilised.

He made the remarks to the media in London on Sunday, The News International reported.

Sharif has been residing at the Avenfield flats owned by his son Hasan Nawaz in London since November 20.

The former premier has been diagnosed with an immune system disorder causing low platelet count.

Also addressing the media, Sharif's personal physician Adnan Khan said the former leader's diseases were being reviewed from every aspect, adding that they were waiting for the clearance from the hematologist as the reasons behind the platelets issue could not be determined.

Serving a seven-year jail term in a corruption case, Sharif had been released on medical grounds for eight weeks by the the Islamabad High Court on October 27.

The Lahore High Court later directed the government to remove his name from the Exit Control List for four weeks so that he could fly abroad for his treatment as suggested by various medical boards.