May 25 (Reuters) - Apple Inc has told its suppliers to speed up iPhone development after China's strict COVID-19 lockdowns hampered schedule for at least one of the new phones, Nikkei reported on Wednesday, citing multiple sources with knowledge of the matter.

Lockdowns due to China's zero-COVID policy led iPhone assembler Pegatron Corp to suspend operations at its Shanghai and Kunshan plants earlier this year.

Financial hub Shanghai remains largely paralysed by a city-wide lockdown, which is now in its seventh week, while Beijing has ramped up quarantine efforts.

Apple last month forecast bigger problems as COVID-19 lockdowns snarled production and demand in China, with the war in Ukraine adding to the iPhone maker's woes.

In the worst-case scenario, Apple expects the manufacturing schedule and initial production volumes of the new phones to be hurt, the Nikkei business daily reported.

Foxconn declined to comment on the matter, while Apple and Pegatron did not respond to Reuters' requests for comment. (Reporting by Tanvi Mehta in Bengaluru; Editing by Subhranshu Sahu and Rashmi Aich)