US President Joe Biden equated his Chinese counterpart Xi Jinping with "dictatorial" leaders as he spoke Tuesday at a Democratic Party fundraiser in the presence of the press.

Biden told participants at the ceremony, which was held in Northern California, that the incident in February of the United States shooting down a Chinese balloon, believed to be for espionage, angered the Chinese president.

"The reason Xi Jinping was so upset when I dropped the balloon that contained two boxes full of spying equipment was because he didn't know it was there," the US president added.

"I'm talking seriously. This is the great embarrassment of dictators, when they don't know what's going on."

Biden indicated that the balloon "was not supposed to go where it was (...) and he (Xi) did not know anything about it," adding, "When it was shot down, he felt very embarrassed and denied being there."

The 80-year-old Biden, who is running for a second term, also played down concerns about the Asian giant, telling donors that "China is facing real economic difficulties."

These statements are likely to raise strong objections from Beijing, which US Secretary of State Anthony Blinken visited just days ago in an attempt to reduce tensions between the two world powers.