US President Joe Biden spoke with the ruler of Oman, amid White House concerns about China’s efforts to deepen its defense presence in the Middle East.

Biden and Haitham bin Tariq Al Said, the sultan of Oman, discussed “the latest developments in the region,” the White House said in a brief statement Friday, promising a fuller readout later.

The president met with senior advisers recently to discuss worries that the Chinese plan to build a military facility in Oman, according to people familiar with the matter, part of a broader effort by Beijing to deepen defense and diplomatic ties in the Mideast.

Earlier: Biden Briefed on Chinese Effort to Put Military Base in Oman

Biden was told Chinese military officials discussed the matter last month with Omani counterparts, who were said to be amenable to such a deal, said the people, who asked not to be identified to discuss private deliberations. The people said the two sides agreed to more talks in the coming weeks.

The precise location of the possible military facility or what it would house is not known. One of the people familiar with the matter described the Chinese role as more of a military presence than an actual facility or base.

The Pentagon has been saying for years that China wants to build more overseas military logistics facilities in the region.

A facility there would amount to a challenge to the US, whose Central Command oversees troops stationed around the region. Oman also sits near the Strait of Hormuz, one of the most vital shipping lanes for oil and liquefied natural gas.

China’s Foreign Ministry said in a statement Tuesday that cooperation with Oman “has yielded fruitful results.”

“The two sides have a high degree of consensus on further developing bilateral relations and deepening cooperation in various fields, aiming to deepen the bilateral friendship and benefit the two peoples,” it said.

Oman is often referred to as the Switzerland of the Middle East for its policy of neutrality. The country regularly acts as a mediator, including between the US and Iran.

Biden in recent weeks has held a series of calls with Mideast leaders as he seeks to prevent the conflict between Israel and Hamas — which has been designated a terrorist organization by the US and European Union — from escalating.

(Updates with additional details, background from sixth paragraph)