Economists have also expressed skepticism about China’s potential to purchase tens of billions of dollars of additional products from the United States, arguing that the American economy is already operating near its full potential. If China does ramp up purchases of energy and agricultural goods, they say, it would simply displace those purchases from other nations, making little lasting impact on the overall trade deficit or the American economy.

The figure offered last weekend follows earlier statements by senior Trump administration officials, who said after a meeting with the Chinese in mid-May that Beijing had proposed a package of purchases and economic reforms that would essentially allow $200 billion worth of American goods to enter China over the next few years.

As that round of talks concluded in mid-May, the White House said that China had committed to buying more agriculture and energy exports, but noted that American officials would travel to China to work out the details of their agreement.

The push to strike a deal with China has also provoked criticism from some lawmakers. The Trump administration briefed lawmakers two weeks ago on a deal that would keep the Chinese telecom firm ZTE in business in exchange for other trade concessions, a proposal that the president later confirmed on Twitter.

The United States had banned the Chinese firm from buying American technology components for seven years as a punishment for violating United States sanctions against Iran and North Korea. The prospect of lifting those sanctions had provoked a backlash from lawmakers across the political spectrum, who saw the issue as a law enforcement matter and ZTE’s expansion in the United States as a potential national security threat.

The trade conflict with the Chinese could escalate in coming months, putting at risk multinational businesses that depend on China to source and sell products. China has threatened to retaliate by placing its own tariffs on roughly $50 billion of American products, and Mr. Trump responded by threatening tariffs on an additional $100 billion of Chinese goods.