WASHINGTON (REUTERS, BLOOMBERG) - US President Donald Trump said his tariffs on Chinese goods are causing companies to move production out of China to Vietnam and other countries in Asia, and added that any agreement with China cannot be a "50-50" deal.

In an interview with Fox News Channel recorded last week and aired on Sunday (May 19) night, Trump said that the United States and China "had a very strong deal, we had a good deal, and they changed it. And I said that's OK, we're going to tariff their products".

Trump also said he was "very happy" with the trade war and that China wouldn't become the world's top superpower under his watch.

"We're taking in billions of dollars," Trump said when asked about the end game on the trade war. "China is obviously not doing well like us."

Trump's comments signal he is in no rush to get back to negotiating with Beijing after talks to end the trade conflict fell apart earlier this month.

No further trade talks between top Chinese and US trade negotiators have been scheduled since the last round ended on May 10 - the same day Trump raised the tariff rate on US$200 billion (S$275 billion) worth of Chinese products from 10 per cent to 25 per cent.

Trump took the step after China soured the negotiations by seeking major changes to a deal that US officials said had been largely agreed.

Since then, China has struck a sterner tone in its rhetoric, suggesting that a resumption of talks aimed at ending the 10-month trade war between the world's two largest economies was unlikely to happen soon.

Trump, who said the interview with Fox News host Steve Hilton had taken place two days after he raised the tariffs, said he would be happy to simply keep tariffs on Chinese products, because the United States would be taking in US$100 billion or more in tariffs.

But he added that he believed that China would eventually make a deal with the United States "because they're getting killed with the tariffs, China's getting totally killed".

But he said that he had told Chinese President Xi Jinping before the most recent rounds of talks that any deal could not be "50-50" between the two countries and had to be more in favour of the United States because of past trade practices by China.

Trump also said that Democratic presidential candidate and former US vice-president Joe Biden should be investigated over a conservative author's allegation that Biden's son Hunter Biden took advantage of his father's position to sign a lucrative business deal with state-controlled Bank of China.

The allegation was made in Peter Schweizer's 2018 book "Secret Empires."

Asked if this should be investigated, Trump said: "100 per cent. It's a disgrace and then (Joe Biden) says China's not a competitor of ours. China is a massive competitor of ours. They want to take over the world."