China reportedly staged a flyover near Taiwan and Japan and sent ships in around the hotly contested South China Sea over the weekend, the Associated Press reported Sunday. The show of force came amid increased tensions regarding President-elect Donald Trump’s recent slights against China's economy and foreign policies.

Though the Chinese government issued statements saying the acts were a routine exercise, the timing of such military displays against Taiwan, which it doesn’t recognize as independent, and oldest rival Japan comes following Trump’s call with Taiwan President Tsai Ing-win earlier this month.

The report said China flew 10 planes Saturday over the Miyako Strat, which sits between Miyako Island and Okinawa Island in the Pacific Ocean and directly over Japanese airspace, and four other planes went over the Bashi Channel that rests beside Taiwan, a statement from Taiwan’s defense ministry read.

That was followed Sunday by three ships patrolling the Senkaku islands, located in the East China Sea but controlled by Japan, a claim disputed by China.

Through his Twitter account, Trump called out China for what he considers unfair trade policies and currency manipulation after stating Tsai had reached out to him and not the other way around. Trump continued to poke China during an interview with Fox News Sunday.

"I fully understand the one-China policy,” Trump said, “but I don't know why we have to be bound by a one-China policy unless we make a deal with China having to do with other things, including trade."

In kind, China said it has “serious concern” regarding his latest comments and said relations with the U.S. could be strained.

“We urge the new U.S. leader and government to fully understand the seriousness of the Taiwan issue, and to continue to stick to the one-China policy,” a spokesman for China’s foreign ministry, Geng Shuang, said according to the AP.