By Donna Borak, CNN

(CNN) -- Treasury Secretary Steven Mnuchin on Monday made clear there's only one person leading trade negotiations with China: President Donald Trump.

"It's clear that President Trump is going to be the one who leads the negotiations, and the team will be an inclusive team," said Mnuchin during an interview on CNBC's "Squawk Box."

Mnuchin's message was echoed by the President himself, who boasted on Twitter about his relationship with his Chinese counterpart President Xi Jinping while his Treasury secretary was still speaking on television.

"He and I are the only two people that can bring about massive and very positive change, on trade and far beyond, between our two great Nations. A solution for North Korea is a great thing for China and ALL!" Trump tweeted.

Over the weekend, the leaders of the world's largest trading partners struck a temporary truce, with Trump agreeing to maintain the 10% tariffs on $200 billion worth of Chinese goods, and not raise them to 25% "at this time," ahead of a January 1 deadline.

In exchange, China agreed it was willing to purchase a "very substantial" amount of agriculture, energy and other goods from the United States to help reduce the trade imbalance -- an achievement Trump also touted on Twitter, saying "Farmers, I LOVE YOU!"

It will now be up to US and Chinese negotiators to craft a deal with "real agreement" on "specific action items and deliverables and timeframes," said Mnuchin in the interview.

Trump has fostered rivalries among his closest advisers on China, pitting former Wall Streeters such as Mnuchin and National Economic Council Director Larry Kudlow against China hawks such as Robert Lighthizer, the US trade representative, and Peter Navarro, a former economics professor who is now Trump's China trade adviser.

In an early morning interview on National Public Radio, Navarro -- who has clashed with his White House colleagues on how the US should proceed in its negotiations with China -- suggested that Lighthizer would be overseeing negotiations.

The internal divisions among top White House aides have complicated negotiations with the Chinese.

Yet Mnuchin reiterated that the Trump administration was committed to reaching a resolution.

"This is not going to be something where there is soft commitments that get kicked down the road," Mnuchin said on CNBC. He described the President's discussion with Xi as "very, very specific."

Mnuchin told reporters at the White House that both leaders -- Trump and Xi -- have extended invitations to their respective countries, but no specific time or date has been set for the next round of talks.

"My expectation is that with all these issues, they will be meeting in the near future," he said.

Mnuchin added that there would be changes to the US agricultural sector "right away," a signal to US soybean farmers who have been the first to feel pain from Chinese retaliation.

The Treasury secretary said on CNBC that the Chinese government had made $1.2 trillion in additional commitments to buy US goods, including on agriculture.

He also said there would be an "immediate focus on reducing auto tariffs," after the President announced China would be willing to "reduce and remove" levies on US automakers from 40%.

Trump didn't specify when the change would happen or what the new tariff level would be.

Chinese Foreign Ministry spokesman Geng Shuang declined to comment Monday on Trump's statement, referring questions to "the relevant authorities."

Ahead of this weekend's meeting, the President had directed his top trade negotiator to "examine all tools" available to address significantly higher tariffs imposed by China on US automakers.

The secretary said there were several meetings in advance of the leaders' meeting in Buenos Aires and no decisions were made until the two presidents met over a steak dinner.

Mnuchin signaled there was a big difference in tone on Saturday with a "very genuine offer" by Xi to Trump. The President described the meeting as "extraordinary" and as a "BIG leap forward" in US-China relations in another tweet earlier Monday morning.

The Treasury secretary also added pressure on Chinese negotiators to keep their promises to the American President, noting that Trump has ample "tools in the toolbox" to escalate tariffs on Beijing if talks don't proceed as planned.

"I'm taking President Xi at his word on his commitment to President Trump, but they have to deliver on this," Mnuchin told reporters. "The President has been clear he expects to move forward, but he has reserved the ability to do additional tariffs if they're not successful."

The secretary offered some buffer for negotiators on what could be achievable over the next 90 days, saying not every single one of the 142 items on the list would need to be completed, noting there could be a "phased-in approach."