Meanwhile Wang Xiaolong, director general of the Foreign Ministry's department of worldwide economic affairs, said negotiations between Chinese and USA officials were making some progress. They have also agreed to exchange visits at the appropriate time.
"In a friendly and candid atmosphere, the two presidents had profound discussions that lasted for two-and-a-half hours".
Working teams on both sides will follow the guidance of the principled consensus reached between the two leaders, and step up negotiations toward the removal of all additional tariffs so as to reach a mutually-beneficial agreement at an early date.
Trump launched the bitter row earlier this year by implementing tariffs on billion of dollars in goods from China, which he accuses of market barriers and predatory practices that Washington says make fair trade impossible.
The US decision to agree to a delay in the imposition of the tariffs formerly scheduled for January 1 might yet be seen as a successful application of leverage.
As the G20 summit closed in Buenos Aires yesterday, the world is eagerly watching whether the talks between the United States and Chinese leaders in Argentina would help defuse the damaging trade war between the world's two largest economies.
Trump left immediately to board Air Force One for Washington, having spent two days attending the summit of G20 countries.
China, which has already slapped tariffs on $110 billion in U.S. goods, is likely to retaliate, ramping up a conflict that is already rattling financial markets and causing forecasters to downgrade the outlook for global economic growth.
But one thing is clear-the stakes in the negotiations between the US and China are huge.
With the United States and China clashing over commerce, financial markets will take their lead from the results of the talks, widely seen as the most important meeting of USA and Chinese leaders in years.
A senior United States official told Reuters that it was the first time that the G20 had recognised that the WTO was "currently falling short of meeting its objectives" and needed reform.
Xi told Trump that only through cooperation could the United States and China serve the interest of peace and prosperity. China has agree to immediately USA agricultural products again in a trade war truce struck December 1, 2018.
Manchester United lack mad dogs with spirit - Jose Mourinho
We don't have many mad dogs - the ones that bite the ball and press all the time. "I thought he was outstanding today", Mourinho added.
"I hope they understand that", he said.
Trump and Xi were seated across from each other in the middle of the table, surrounded by their respective delegations. The world's two biggest economies have also increasingly been at odds over security in the Asia-Pacific region.
In a long-sought concession to the U.S., China agreed to label fentanyl, the deadly synthetic opioid responsible for tens of thousands of American drug deaths annually, as a controlled substance.
At Trump's request, China agreed to label fentanyl a controlled substance due to its contribution to the U.S. opioid crisis.
The White House also said that China's government is "open to approving" the purchase of Dutch semiconductor manufacturer NXP by American chipmaker Qualcomm.
In a release from White House Press Secretary Sarah Huckabee Sanders, Trump said, "This was an awesome and productive meeting with unlimited possibilities for both the United States and China".
Observers feared that if no progress was made at the Trump-Xi dinner, the USA president would make good on his threat to double the amount of Chinese goods facing punitive taxes, and escalate tariffs to a 25 percent level at the start of the new year.
Officials expressed relief that agreement on the summit communique was reached after negotiators worked through the night to overcome differences over language on climate change.
He cited "market access restrictions, weak intellectual property rights protection, unfair industrial policies, the slow pace of economic reforms and lack of regulatory transparency".
Trump and Merkel discussed trade, the conflict between Ukraine and Russian Federation, and Moscow's violations of a landmark nuclear arms treaty that Trump plans to exit.
But it was the United States and China that dominated the spotlight. The stock market has wobbled this year amid those concerns, and would probably sink if Trump went from 10% tariffs to 25%.