“If I didn’t get elected, he definitely would not be spending $10 billion,” President Donald trump said Wednesday, referring to Terry Gou, chairman of Taiwanese Apple (AAPL) supplier Foxconn.

That evening, Trump announced Foxconn’s plans to build a plant in Wisconsin that would produce flat-screen display panels for TVs and other products. The plant would create 3,000 jobs and represent a $10 billion investment, according to White House officials.

While the investment echoed Trump’s promise to “bring jobs back” to the US, the president can hardly take all the credit for Foxconn’s big move. The relocation of China’s manufacturing industry has been going on for years, as the long-time cost advantage of manufacturing in China has slowly declined. Lower input costs, strong demand in the US market and financial support from US state governments has accelerated the comeback of “made in America.”

China is not as cheap anymore

As the world’s largest contract electronics maker, Foxconn operates 12 factories in China. It has faced criticism in the past for paying its workers minimum wage and requiring them to work long hours. In 2010, Foxconn doubled the monthly salary to $290 month after reports emerged that at least 10 workers had committed suicide.

Since then, though, it’s gotten more expensive to manufacture goods in China. In the past five years, wages in China have grown about 10% to 15% every year, while the increase in the US is about 2.5%, official data from both countries indicates. Boston Consulting Group says industrial electricity prices in the US are 30% to 50% lower than in other major export nations. Foreign manufacturers that make products in the US also save money on shipping time and cost since many customers are here.

Overall, China’s manufacturing cost advantage over the US shrank from 14% in 2004 to only 1% in 2016, according to research from BCG.

“The disparity has been driven by things like increasing wages and energy cost in China [and] productivity gains relatively in the US,” Rahul Choraria, principal at BCG, told Yahoo Finance. “Production is likely to be more local for local consumption.”

As a result of all of these factors, Chinese manufacturers have been building more factories in the US to save money — in the same way US manufacturers have moved jobs offshore. This trend predated the election of Donald Trump.

“We’ve seen this trend start since about 2009, and there’s been an uptick especially in the past two years,” said Cassie Gao, an analyst at Rhodium Group. Rhodium’s China Investment Monitor shows Chinese companies are spending billions on new projects and expansions of existing US subsidiaries.