A U.S. military helicopter and fighter jet crashed in the South China Sea about 30 minutes apart, incidents that coincide with a visit by U.S. President Donald Trump to Asia.

A Sea Hawk helicopter went down about 2:45 p.m. on Sunday ¡°while conducting routine operations from the aircraft carrier USS Nimitz,¡± the U.S. Navy said in a post on X. A Navy official said no details on the location of the carrier would be provided due to operational security.

Then at about 3:15 p.m., an F/A-18F Super Hornet also crashed, the Navy said on Monday, adding that all five people involved in the accidents were safe and investigations were underway. No details have been released yet on the suspected causes of the incidents.

The carrier strike group was in the South China Sea region on the final leg of its deployment before heading back to the U.S. West Coast, according to U.S. Naval Institute News, which tracks carrier groups.

U.S. President Donald Trump said he was aware of the incident but didn¡¯t suspect foul play. ¡°They think it might be bad fuel,¡± Trump told reporters aboard Air Force One.

Beijing opposes the U.S. military presence in the South China Sea and claims nearly the entire area while also building numerous artificial islands. Vietnam, the Philippines, Brunei, Malaysia and Taiwan all claim parts of the sea and have sparred with Beijing over where the boundaries fall.

When asked about the crashes, Chinese Foreign Ministry spokesman Guo Jiakun said that ¡°the U.S. is flexing its muscle by sending military aircraft into the South China Sea frequently, and this serves as the root cause for sabotaging regional peace and stability and maritime security issues.¡±

¡°If the U.S. has any requests, then China will provide necessary assistance out of humanitarianism,¡± he added at a regular news briefing in Beijing.

Trump¡¯s visit includes stops in Malaysia as well as Japan and South Korea, which are both U.S. allies. During the trip, U.S. and Chinese trade negotiators agreed on handling a range of contentious points, spanning tariffs, shipping fees, fentanyl and export controls. That sets up Trump and China President Xi Jinping to finalize a deal during a meeting scheduled for later in the week.