"China has been very insistent that existing tariffs must be done away with in any deal, so the announcement shows the USA giving way in the face of Beijing's core interests", said Dr Huo, who is vice-chairman of the China Society For World Trade Organisation Studies.
In a step towards a trade deal, Beijing on November 7 announced that China and the USA agreed to remove additional tariffs on their goods, local media reported.
Gao's comments lifted stocks and market futures in Asia and the United States amid a general sense of optimism that tensions are ratcheting down.
The official, who spoke on condition of anonymity, said it was still possible the partial agreement would not be reached, but a deal was more likely than not.
The idea of a tariff rollback was not part of the original October "handshake" deal between Chinese Vice Premier Liu He and U.S. President Donald Trump, these sources said.
The U.S. has placed tariffs on more than $360 billion of Chinese goods amid its more than year-long trade war with Beijing. -China trade war, inadvertently recognizing Taiwan as a separate country from China while still paying lip service to Beijing.
The spokesman said that Chinese and American negotiating teams have reached a consensus following "extensive, constructive and serious" talks in recent weeks.
"If the two sides achieve a "Phase 1" agreement, then based on the content of that agreement, tariffs already increased should be canceled at the same time and by the same rate", Gao said.
Throughout the report, the United Nations treats Taiwan as a separate country with its own economy that is clearly not subject to tariffs directed at China.
"This data offers concrete proof that tariffs are taxes paid by American businesses, farmers and consumers - not by China", Americans for Free Trade spokesperson Jonathan Gold said in the Tariffs Hurt the Heartland's analysis.
Most of the recent market optimism, however, has been fuelled by the increasing chance of a mini trade deal between the USA and China.
The increased revenue was the result of the USA levying a new 15 percent tariff on $111 billion of Chinese goods beginning September 1.
The proportion of tariffs cancelled must be the same, and how many tariffs should be cancelled can be negotiated, Gao told reporters.
The Oct. 12 agreement helped to ease financial market jitters, but the two sides have yet to report progress on major disagreements over technology and other irritants following 13 rounds of talks.
The official said China was believed to see a quick deal as its best chance for favorable terms, given pressure Trump is facing from a congressional impeachment inquiry as he seeks re-election in 2020. But some say issues such as stances toward intellectual property could be behind the delay. He gave no indication whether or not rolling again tariffs was a risk at this stage.