By Parisa HafeziDUBAI, Aug 12 (Reuters) - There have been no talks on extending a ceasefire between Iran and the U.S. under an interim deal, with Iran saying that Washington ‌must return to the pact and define a timeframe to implement its commitments, a senior ‌Iranian source told Reuters on Wednesday. The source's comments came after Turkey's Anadolu news agency, citing Pakistani government sources, reported that ​Tehran and Washington had agreed to extend a 60-day ceasefire under their Memorandum of Understanding (MoU). Advertisement AdvertisementAdvertisement Advertisement"One of the issues that is being discussed via mediators is the U.S. returning to the interim agreement and defining a timeframe for implementing its commitments. However, efforts to secure a lasting peace have hit an impasse over ‌a range of issues, including disagreements over the Strait ​of Hormuz. are not engaged in talks and Tehran will not start them as long ​as Washington breaches the interim deal, adding that messages are being exchanged via intermediaries ​Pakistan and Qatar.