Trump told reporters his administration will notify about 200 countries soon of their new "world tariff" rate.
"I would say it'll be somewhere in the 15 to 20 per cent range," Trump told reporters, sitting alongside UK Prime Minister Keir Starmer at his luxury golf resort in Turnberry, Scotland.
"Probably one of those two numbers."
Trump, who has vowed to end decades of US trade deficits by imposing tariffs on nearly all trading partners, has already announced higher rates of up to 50 per cent on some countries - including Brazil - starting on Friday.
The announcements have spurred feverish negotiations by a host of countries seeking lower tariff rates including India, Pakistan, Canada and Thailand among others.
The US president on Sunday clinched a huge trade deal with the European Union that includes a 15 per cent tariff on most EU goods, $US600 billion ($A920 billion) of investments in the US by European firms and $US750 billion in energy purchases over the next three years.
That followed a $US550-billion deal with Japan last week and smaller agreements with the United Kingdom, Indonesia and Vietnam.
Other talks are ongoing, including with India, but prospects have dimmed for many more agreements before Friday - Trump's deadline for deals before higher rates take effect.
Trump has repeatedly said he favours straightforward tariff rates over complex negotiations.
"We're going to be setting a tariff for essentially, the rest of the world," he said again on Monday.
"And that's what they're going to pay if they want to do business in the United States. Because you can't sit down and make 200 deals."
Canadian Prime Minister Mark Carney said on Monday trade talks with the US were at an intense phase, conceding that his country was still hoping to walk away with a tariff rate below the 35 per cent announced by Trump on some Canadian imports.
Carney conceded this month that Canada - which sends 75 per cent of its exports to the United States - would likely have to accept some tariffs.
US and Chinese economic officials met in Stockholm on Monday for more than five hours of talks aimed at resolving longstanding economic disputes, seeking to extend a truce on tariffs by three months.
US Treasury Chief Scott Bessent was part of a negotiating team that arrived at Rosenbad, the Swedish prime minister's office in central Stockholm, in the early afternoon.
China's Vice Premier He Lifeng was also seen at the venue.
China is facing an August 12 deadline to reach a durable tariff agreement with Trump's administration, after the two governments reached preliminary deals in May and June to end weeks of escalating tit-for-tat tariffs and a cut-off of rare earth minerals.
Negotiators from the two sides were seen exiting the office about 8pm and did not stop to speak with reporters.
The discussions are expected to resume on Tuesday.
Trump touched on the talks during a wide-ranging press conference with UK Prime Minister Keir Starmer in Scotland.
"I'd love to see China open up their country," Trump said.
Without an agreement, global supply chains could face renewed turmoil from US duties snapping back to triple-digit levels that would amount to a bilateral trade embargo.
Trade analysts said another 90-day extension of a tariff and export control truce struck in mid-May between China and the United States was likely.
