In an opinion piece in the Samoa Observer he called this view ignorant, or prejudiced.
Earlier this month, an American official claimed China was "using predatory economics" and "debt for sovereignty deals".
But Mr Chao called this ridiculous.
Claims that loans from China are a quid pro quo for recipient nations' political sovereignty is "Cold War" thinking not supported by evidence, he said.
"China's foreign aid is offered on the basis of equality, with full respect for the will of the governments and people," he wrote.
"It comes without interfering in their domestic affairs or attaching any political strings."
The ambassador said Samoan-Chinese relations were built on mutual respect, trust and support, and that 38 percent of Samoa's $US1.1 billion national debt was owed to China.
He cited research from the Australian National University which he said found that China held less than 12 percent of debt owed by Pacific states.
The ambassador also noted figures from Australian think-tank the Lowy Institute which he said showed that China spent US$1.1 billion in aid in the Pacific in the decade to 2016, compared to US$5.2 billion by Australia over a similar period.