Apple has asked suppliers to ensure that shipments from Taiwan to China strictly comply with Chinese customs regulations after a recent visit by senior U.S. lawmaker Nancy Pelosi to Taipei stoked fears of rising trade barriers. From a report: Apple told suppliers on Friday that China has started strictly enforcing a long-standing rule that Taiwanese-made parts and components must be labeled as being made either in "Taiwan, China" or "Chinese Taipei," sources familiar with the matter told Nikkei Asia, language that indicates the island is part of China. The U.S. tech titan urged suppliers to treat the matter with urgency…