Huawei Technologies Co., whose products have been targeted as a national security risk by the U.S. and other governments, faces a new hurdle: reduced access to the global financial system.

Two banks that helped power the Chinese company’s rise as a global technology supplier, HSBC Holdings PLC and Standard Chartered PLC, won’t provide it with any new banking services or funding after deciding that Huawei is too high risk, people familiar with those decisions said.

While HSBC made its decision last year, Standard Chartered moved more recently as concerns about Huawei escalated this year from a Justice Department investigation into whether the company violated U.S. sanctions on Iran, some of the people said.

A third key bank, Citigroup Inc., continues to provide Huawei with day-to-day banking services outside the U.S., people familiar with that relationship said. New banking business would be subject to review, and Citigroup is monitoring developments in the U.S., the people said.

This month, Huawei finance chief Meng Wanzhouwas arrested in Canada and awaits possible extradition to the U.S. to face charges over alleged sanctions violations and bank fraud. Her arrest has heightened trade tensions between the U.S. and China and has resulted in a diplomatic spat between China and Canada. Ms. Meng, who denies any wrongdoing, is out on bail with strict limits on her movements.