(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.

Tong was also slated to speak at a Washington-based think tank in early July but the State Department asked for that event to be canceled as well. That speech was ultimately rescheduled for after Tong's scheduled retirement later that month meaning he eventually had the opportunity to speak about Hong Kong but as a former official.

The Financial Times first reported some details of the President's commitment.

At the time, reporters asked State Department spokeswoman Morgan Ortagus if Tong was barred from making a tough speech after Trump and Xi's trade truce during the G20 summit.

"I believe that that was based off of anonymous reports, and that's not something that we ever validate here at the State Department. I don't see much truth to that," she responded.

Trump has deferred to China on the situation in Hong Kong when asked about it publicly in recent months.

"Well, something is probably happening with Hong Kong because when you look at, you know, what's going on, they've had riots for a long period of time. And I don't know what China's attitude is," Trump told reporters on the South Lawn of the White House on August 1.

"Somebody said that at some point they're going to want to stop that. But that's between Hong Kong and that's between China, because Hong Kong is a part of China. They'll have to deal with that themselves. They don't need advice," he added.

He echoed that sentiment in a tweet on August 14.

"I know President Xi of China very well. He is a great leader who very much has the respect of his people. He is also a good man in a 'tough business.' I have ZERO doubt that if President Xi wants to quickly and humanely solve the Hong Kong problem, he can do it. Personal meeting?"