Last month, Djibouti ended its contract with Dubai's DP World, one of the world's biggest port operators, to run the Doraleh Container Terminal, citing failure to resolve a dispute that began in 2012.
DP World called the move an illegal seizure of the terminal and said it had begun new arbitration proceedings before the London Court of International Arbitration.
During a congressional hearing on Tuesday, which was dominated by concerns about China's role in Africa, lawmakers said they had seen reports that Djibouti seized control of the port to give it to China as a gift. China has already built a military base in Djibouti, just miles from a critical U.S. military base.
"If this was an illegal seizure of that port, what is to say that government wouldn't illegally terminate our lease before its term is up," said Representative Bradley Byrne, a Republican.
In a letter to U.S. Defense Secretary Jim Mattis, Byrne said he was concerned about China's influence in Djibouti and the impact it would have on U.S. military and intelligence assets.
Djibouti is strategically located at the southern entrance to the Red Sea on the route to the Suez Canal.
Marine General Thomas Waldhauser, the top U.S. military commander overseeing troops in Africa, said that if China placed restrictions on the port's use, it could affect resupplying the U.S. base in Djibouti and the ability of Navy ships to refuel there.
"If the Chinese took over that port, then the consequences could be significant," Waldhauser said during the House of Representatives Armed Services Committee hearing.
Djibouti hosts a vital U.S. military base that is home to about 4,000 personnel, including special operations forces, and is a launchpad for operations in Yemen and Somalia.
"There are some indications of (China) looking for additional facilities, specifically on the eastern coast. ... So Djibouti happens to be the first,; there will be more," Waldhauser said.
China has sought to be visible in Africa, including through high-profile investment in public infrastructure projects, as it deepens its trade ties.
"We'll never outspend the Chinese in (Africa)," Waldhauser said, noting some of the Chinese investments in Djibouti.
U.S. Secretary of State Rex Tillerson said on Tuesday the United States will give more than $533 million in humanitarian aid for victims of conflicts and drought in Ethiopia, Somalia, South Sudan and the West and Central African countries bordering Lake Chad.
But Tillerson contrasted the United States' work on the African continent, which he said promoted "sustainable growth," with that of China, which recently pledged $124 billion for its Silk Road plan to expand links between Asia, Africa, Europe and other places.
Tillerson said China's investment in Africa "encouraged dependency."
Earlier this year, the U.S. military put countering China, along with Russia, at the center of a new national defense strategy.
The Pentagon said China was a part of "revisionist powers" that "seek to create a world consistent with their authoritarian models."
Waldhauser said he was in the process of rewriting U.S. military strategy in the region with China in mind.
"China has been on the African continent for quite some time, but we as a combatant command have not dealt with it in terms of a strategic interest," Waldhauser said.
"We are taking baby steps in that regard," he added.
(This story has not been edited by NDTV staff and is auto-generated from a syndicated feed.)
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