The US has accused China of blocking the ASEAN members accessing more than USD 2.5 trillion in recoverable energy reserves in the South China Sea by illegal construction activities. China claims almost all of the South China Sea. Vietnam, Philippines, Malaysia, Brunei and Taiwan have counter-claims over the area.

"China's illegal island-building in international waterways is not simply a security matter. By blocking development in the South China Sea through coercive means, China prevents the ASEAN members from accessing more than USD 2.5 trillion in recoverable energy reserves," Pompeo said in his address at CERAWeek in Houston Tuesday night. To contrast, the US Government promotes energy security for those Southeast Asian nations, he said in his address to one of the largest gathering of global energy leaders.

"We want countries in the region to have access to their own energy. We want to help them. We want to create partnerships. We want transparent transactions, not debt traps. We explore responsibly," he said. But, China does not play by that same set of rules, he alleged.

"Its values are simply different. You see that in places as diverse as Africa, where they often ship in their own labour, creating jobs for Chinese workers rather than for those in the local economy," he said. "It's using the debt trap which I referred to just a moment ago to put these countries in a place where it is not a commercial transaction, it's a political transaction designed to bring harm and political influence in the country in which they're operating," Pompeo said.

"And we all know the story in Russia," he said. It invaded Ukraine to gain access to oil and gas reserves. It in turn deprived Ukraine of the possibility of developing those resources for itself and using its pipelines and its networks to bring energy to its own people. Rather, it uses those pipelines to put pressure – political pressure – on the people of Ukraine, he alleged.