US fast food chain McDonald's has apologized for a global technology outage that affected many of its restaurants around the world.

The Chicago-based company released a statement on Friday about the trouble that forced many McDonald's outlets in Japan and elsewhere to temporarily close.

It said the system outage occurred at approximately midnight on Friday, US Central Daylight Time. It said many markets around the world were already back online and that the company is closely working with those that remain affected.

The statement said the incident "was not directly caused by a cybersecurity event," but by "a third-party provider during a configuration change."

It said, "Reliability and stability of our technology are priority." The statement added, "What happened today has been an exception to the norm, and we are working with absolute urgency to resolve." The company said, "We sincerely apologize for any inconvenience this has caused."

In Japan, the system failure struck on Friday afternoon, causing many outlets to suspend operations for hours or for the rest of the day. Some shops continued to offer service by taking orders manually without using the system.

McDonald's Japan says some outlets in the country had resumed operations by Friday evening after the system was partially restored.