(CNN) During a private phone call in June, President Donald Trump promised Chinese President Xi Jinping that the US would remain quiet on pro-democracy protests in Hong Kong while trade talks continued, two sources familiar with the call tell CNN.

The remarkable pledge to the Chinese leader is a dramatic departure from decades of US support for human rights in China and shows just how eager Trump is to strike a deal with Beijing as the trade war weighs on the US economy.

And like other calls with the leaders of Ukraine, Russia and Saudi Arabia, records of Trump's call with Xi were moved to a highly-classified, codeword-protected system, greatly limiting the number of administration officials who were aware of the conversation.

Trump's commitment to China had immediate and far-reaching effects throughout the US government as the President's message was sent far and wide.

In June, the State Department told then-US general counsel in Hong Kong, Kurt Tong, to cancel a planned speech on the protests in Washington because the President had promised Xi no one from the administration would talk about the issue.

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