Tensions between Donald Trump and one of his top trade negotiators have been brought into the open as the two disagreed publicly about the definition of a memorandum of understanding.

In a White House meeting between US officials and China’s top negotiator, which was televised and attended by journalists, Robert Lighthizer, the US trade representative, contradicted the president’s claim that memoranda of understanding (MOU) are non-binding.

“I don’t like MOUs because they don’t mean anything. To me they don’t mean anything. I think you’re better off just going into a document,” said Trump during Friday’s exchange.

Lighthizer, who was brought into the White House team because of his anti-China credentials, then jumped in to clarify: “An MOU is a contract, it’s the way trade agreements are generally used. People refer to it like it’s a term sheet. It’s not a term sheet it’s an actual contract between the two parties.”

Trump was unhappy with Lighthizer’s definition, saying: “By the way, I disagree, I think that memorandum of understanding is not a contract to the extent we want. We’re gonna have – we’re doing a memorandum of understanding that will be put into a final contract, I assume, but to me the final contract is really the thing … that means something.”

The two went back and forth, with Lighthizer saying they would no longer use the term “memorandum of understanding”, but would instead call it a “trade agreement”.

“Good, I like that much better,” said Trump. “I wouldn’t go into a memorandum, I would go right into a trade agreement. Either you’re gonna make a deal or you’re not. To have these other agreements doesn’t mean anything.”

Lighthizer conceded that there were still “major hurdles” before the US and China can reach a trade agreement.

Talks have continued in Washington throughout the weekend between Lighthizer, US officials and Xi’s special envoy, Liu He.

On Sunday night, Trump tweeted that the talks had been “very productive” and as a result he would delay increasing tariffs of Chinese goods and assuming both sides continued to make additional progress, he would meet Chinese president Xi Jinping at Mar-a-Lago to complete the agreement.