China’s announcement of military drills around Taiwan as U.S. House Speaker Nancy Pelosi visits the island is already having ripple effects across global supply chains, prompting detours and causing delays of energy shipments. 

Gas suppliers are rerouting or reducing speed on some liquefied natural gas vessels currently en route to North Asia, according to people familiar with the matter. Shipments to Taiwan and Japan this weekend will be affected, said the people, who requested anonymity as the information isn’t public.

Shipping companies are reassessing their options after China’s response to the visit of the highest-ranking U.S. official to the island in 25 years. The actions threaten to disrupt one of the world’s busiest waterways. 

Earlier: Taiwan Tensions Raise Risks in One of Busiest Shipping Lanes

China, which regards Taiwan as part of its territory, condemned Pelosi’s visit and said its military exercises would include “long-range live firing” near Taiwan starting as soon as Tuesday evening, as well as more drills encircling the island from Aug. 4. Early Wednesday, state broadcaster CCTV said China had begun joint Navy and Air Force maneuvers in the region.

Ship managers and shipowners said traffic overall through the Taiwan Strait was normal on Wednesday. But as China ramps up military activity in the region, shippers may need to reroute vessels around the eastern side of the island, rather than through the busy waterway between mainland China and Taiwan. That will create delays of about three days, according to shipbrokers.

While the conflict could exacerbate a shortage of LNG amid an energy crunch, delays of a few days aren’t uncommon. Shippers often face typhoons at this time of year that create similar disruptions. 

The military exercises are scheduled to end by next week, and shippers and analysts will be watching to see if it blows over quickly.

“We might be concerned if the drills become longer and more intense to impact supply chains, but there is no sign of that happening now,” says Huang Huiming, a fund manager at Nanjing Jing Heng Investment Management Co.