Jakarta. Newly sworn-in US President Donald Trump’s chief diplomat Marco Rubio had a phone call with Indonesia’s Foreign Minister Sugiono for talks about the South China Sea, among others, on Thursday.

The phone conversation took place just days after Rubio got picked to helm the US Department of State. According to US Department of State’s spokeswoman Tammy Bruce, the discussions revolved around the South China Sea, one of the world’s busiest trade routes that is also seeing contested territorial claims between Beijing and some ASEAN members.

“The two leaders discussed the importance of peace and stability in the Indo-Pacific region, including an exchange of views on maritime security in the South China Sea,”  Bruce said.

Bruce said that the two countries also recognized how crucial US-Indonesia’s comprehensive strategic partnership is to a “secure and prosperous” Indo-Pacific region. They also pledged to deepen trade and investment ties in areas advantageous to both countries. As of writing, the Indonesian government has yet to issue a statement regarding Sugiono’s talks with Rubio.

Rubio, who is also the US first Latino secretary of state, is known for his hawkish stance on China. Just a week ago, Rubio warned that China would be the biggest threat to American prosperity in the 21st century. On his second day back in the White House, Trump had threatened a 10 percent duty on all Chinese imports starting next month after he accused Beijing of allowing the flow of opiate fentanyl into Mexico and Canada.

Indonesia is trying to strike a balance in its relations with the major powers US and China. President Prabowo Subianto repeatedly said that Indonesia would be a friend to all and an enemy to none under his presidency. But shortly after taking office in October, Indonesia announced that it would join the Russia and China-led BRICS bloc of emerging economies, and swiftly snagged a seat in the group almost three months later.

Prabowo also kicked off his first-ever foreign trip with a visit to Beijing to meet his Chinese counterpart Xi Jinping. The talks resulted in a joint statement that made headlines by stating that the two countries had reached a common understanding of overlapping claims over marine areas. Indonesia has denied that it had accepted China’s so-called “nine-dash line”. China has been using these lines to lay claims over 90 percent of the 3 million-square-kilometer South China Sea.