WASHINGTON – Citing national security risks, President Barack Obama on Friday blocked a Chinese company from owning four wind farm projects in northern Oregon near a Navy base where the U.S. military flies unmanned drones and electronic-warfare planes on training missions.

It was the first time in 22 years that a U.S. president blocked such a foreign business deal.

Obama's decision was likely to be another irritant in the increasingly tense economic relationship between the U.S. and China. It also comes against an election-year backdrop of intense criticism from Republican presidential challenger Mitt Romney, who accuses Obama of not being tough enough with China.