The Chinese foreign ministry said on Saturday it was in contact with US officials on the next steps to be taken following an incident earlier this week that has further heightened tensions in the region.

"According to our understanding, the US and Chinese sides are working on appropriately handling this matter through channels between the two militaries," the ministry said in an email sent to multiple news organizations.

Later on Saturday, the Pentagon said that after "direct engagement with Chinese authorities" it had "secured an understanding" that China would return the seized underwater drone, according to the Reuters news agency.

The incident occurred on Thursday afternoon when China intercepted the underwater drone, which the Pentagon said was collecting unclassified scientific data, after the USNS Bowditch (pictured above) stopped to collect it in waters near the Philippines. 

The US has maintained that the drone was unlawfully seized and has called on Beijing to return it. "It is ours. It's clearly marked as ours. We would like it back, and we would like this not to happen again," Pentagon spokesman Jeff Davis said. He added that it could be the first time in recent history that China has seized a US naval vessel.

The Global Times, a Chinese state-run newspaper, quoted an official as saying that the situation was expected to be resolved shortly. "China has received the US request to return the device, communication is open between the relevant departments of the two sides and I believe this matter will obtain a smooth resolution," the official told the newspaper.

Fears of conflict

The incident came shortly after US President-elect Donald Trump raised alarm bells when he announced that he had spoken with the president of Taiwan over the phone in a notable break from presidential protocol. The US has maintained a "one-China" policy toward Taiwan, which Beijing considers its territory.

Not long after the announcement that China had seized the underwater drone, Trump tweeted his outrage over the incident while also provoking laughs on social media for his spelling of "unprecedented" as "unpresidented." He later deleted that tweet and replaced it with a corrected version.

Trump's more aggressive stance toward China - when he indicated that he did not feel "bound by a one-China policy" - has raised concerns that the incoming president could provoke a conflict with Beijing.

US-China relations have also been strained because of Beijing's growing military presence in the South China Sea.

blc/jm (AP, dpa)