Tariffs on US$200 billion (RM813.6 billion) worth of Chinese imports had been set to rise to a prohibitive 25 per cent from the current 10 per cent if no deal was reached by Friday.
But the US threat of tariff increases comes just as China is trying to support its cooling economy, so could offer Trump leverage in the talks. "I believe we'll all be celebrating very soon in the United States and in China", said Selig.
Chamber president Alan Beebe said 47 percent of members wanted the USA government to "advocate more strongly" for a level playing field for US businesses in the world's second-largest economy.
The survey found that 89 percent of businesses reported a pessimistic view on the world's most important bilateral trade relationship. Washington wants Beijing to roll back plans including "Made in China 2025", which calls for government-led creation of global competitors in robotics and other technology.
China also expressed optimism over the trade talks.
Without a delay to the March 1st deadline, the 90-day trade truce agreed upon by President Trump and Chinese President Xi Jinping in December on the sidelines of the G20 summit in Argentina would have come to an end. and import duties on 200 billion USA dollars worth of Chinese goods would have jumped from 10 percent to 25 percent.
US President Donald Trump and his Chinese counterpart Xi Jinping in December declared a truce in their trade war and agreed to hold off on further tariffs or retaliation for 90 days.More news: Lady Gaga takes Oscar for best original song
The trade war was started by Trump over claims of unfair trading practices and intellectual property theft by the Chinese.
"Certainly our members are hopeful that the uncertainty and the loss and the delays in business that have resulted from the trade negotiations and trade frictions will turn out to have been worthwhile in the end", said Tim Stratford, chairman of the chamber.
Trump announced Sunday he would postpone the March 1 increase after weekend talks made "significant progress". Securing some rather minor concessions from China to purchase more soybeans from the US was the easy part, but forcing sweeping changes to its trade practices - the so-called "structural reforms - will be extremely hard, if not potentially unobtainable".
This, taken in conjunction with other measures, would set in motion a process of insourcing, to bring more manufacturing back to the US, which would mean more jobs here.
Companies ranked "bilateral tensions" as a top challenge alongside chronic frustrations with rising costs and vague laws and enforcement.
"A growing number of companies are hedging their bets", the report said.
US standards for power generation, manufacturing, fuel economy and emissions are above and beyond anything China puts upon itself. It said nearly half of companies surveyed believe Chinese policies are enforced differently against them and local rivals.