BEIJING (AP) — Chinese President Xi Jinping is pointing to "some negative factors" that have cropped up in U.S.-China relations since he and President Donald Trump first met less than three months ago.

US President Donald Trump with Chinese President Xi Jinping at Trump's Mar-a-Lago estate after a bilateral meeting in Palm Beach, Florida, on April 7. REUTERS/Carlos Barria BEIJING — Chinese President Xi Jinping warned President Donald Trump on Monday that "some negative factors" were hurting US-China relations, as tensions flare anew over a slew of long-standing sore points.

Xi's comments in a phone call with Trump follow Beijing's displeasure over US arms sales to China's rival Taiwan, US sanctions against a Chinese bank over its dealings with North Korea, and, most recently, the sailing of a US destroyer within the territorial seas limit of a Chinese-claimed island in the South China Sea.

Beijing was also miffed after the State Department gave Beijing a dismal grade last week in a new human-trafficking report.

As reported by state media, Xi told Trump in their call that China expected Washington to continue managing relations on the basis of the "one China" principle that rules out formal contacts with Taiwan, which China claims as its own territory.

"Xi Jinping emphasized that, since my meeting with the president at Mar-a-Lago, China-US relations have achieved important outcomes," the state broadcaster CCTV reported, referring to Xi's meeting with Trump in Florida in April. "At the same time, bilateral relations have been affected by some negative factors. China has expressed its position to the US."

It's unclear whether any of those issues will come up in discussions at the G-20 summit in Germany, where Trump and Xi are expected to hold a bilateral meeting.

But it now appears that China is pushing back against the US pressure, setting the stage for a potential confrontation.

China's foreign ministry accused the US of violating Chinese sovereignty and disrupting "peace, security, and order of the relevant waters" after the US Navy destroyer USS Stethem sailed Sunday within 12 nautical miles, or 14 miles, of the tiny Triton island, which is claimed by China, Taiwan, and Vietnam.

The defense ministry issued a similar statement Monday, saying it would beef up patrols and take precautions commensurate with the threat level to safeguard "national sovereignty and security."

Trump and his top aides have done little to hide their irritation over what they see as the reluctance by China, North Korea's main economic partner, to tighten the screws on Pyongyang over its nuclear and missile programs.

Until lately, American officials had been describing China as a partner in their strategy to prevent North Korea from developing the ability to strike the US mainland with nuclear weapons.

But last month Trump hinted at his loss of patience, tweeting that his bid to secure a tougher Chinese approach "has not worked out."