After suspending his most aggressive tariff plans from earlier this year, Trump this month renewed his threats, sending warning letters to dozens of countries that he intended to start charging high tariffs from 1 August.

His targets included all of America’s biggest trade partners, including the European Union, Canada, Mexico, Japan and South Korea.

Indonesia also received a letter from Trump last week outlining plans for a 32% tariff on its goods, reportedly bewildering officials who had thought an agreement was close.

Trump said on Tuesday he had reduced that rate after a phone call with the president of Indonesia.

He said as part of the deal, Indonesia had agreed to lower its trade tariffs for products from the US, which America has complained, external were high for many agricultural products as well as certain manufactured goods.

“They are going to pay 19% and we are going to pay nothing… we will have full access into Indonesia,” he said.

The country has also agreed to purchase $15bn (£11.2bn) worth in US energy, $4.5bn in American agricultural products and 50 Boeing jets, he later wrote on social media.

Those figures are lower than those outlined in a trade deal Reuters had reported earlier this month was expected to be signed.

Indonesia ranks as one of America’s top 25 trade partners, sending about $28bn to the US last year, including clothing, footwear and palm oil.

Stephen Marks, economics professor at Pomona College in California, said the benefits of the deal to Indonesia “are more political than economic”.

“Certainly, [the US does] have some major imports categories from Indonesia – electronics, apparel, footwear, palm oil products which are used in cosmetics,” he said.

“Relative to total trade, the US is a significant importer from Indonesia, though not as great as some of its Asian trading partners.”

As well as Indonesia, the administration has announced agreements with just the UK, China and Vietnam. In all three of those cases, the deals left high US tariffs in place while key issues and terms went unconfirmed or unresolved.