In Asia, U.S.'s Pompeo expected to bolster allies against China

During Pompeo's trip, which Defense Secretary Mark Esper will join, India is expected to sign an agreement that will give it access to sensitive U.S. satellite data to help improve targeting of missiles and drones, Indian officials said.

"There is great further potential in our defence cooperation," an Indian official said.

Difficult but necessary decision

In what will be the first visit by a U.S. Secretary of State to Sri Lanka in over a decade, Pompeo will advise leaders in Colombo to scale back dependence on China, which has invested billions of dollars building ports and highways but left the island nation in debt, Thompson said.

"We urge Sri Lanka to make difficult but necessary decisions to secure its economic independence for long-term prosperity," Thompson added.

The island is a key part of Chinese President Xi Jinping's Belt and Road Initiative but Colombo has in recent years sought to improve ties with India, United States and Japan.

Similar efforts are under way to push back against Chinese influence in the Maldives, tropical islands that lie on key shipping lanes.

Pompeo's visit to Indonesia comes amid an escalating U.S.-China rivalry that is being vigorously contested in Southeast Asia, especially in the South China Sea, which China claims as almost entirely its own territory. The claim is opposed by many states in the region, including Indonesia.

The State Department this week approved the potential sale of three weapons systems to Taiwan, including sensors, missiles and artillery that could have a total value of $1.8 billion.

Taiwan, which China says is a renegade province, also claims large parts of the South China Sea.

Washington asked Indonesia in July and August to grant landing and refuelling rights to its P-8 surveillance planes, which monitor Chinese military activity in the resource-rich waterway.

The request was rebuffed by President Joko Widodo, according to four senior officials.

"There are commercial issues, security issues and diplomatic issues where the United States has already improved the relationship between the countries," Pompeo said this week. "But there's more that we can do."