US President Donald Trump said on Tuesday that he had struck a trade pact with Indonesia resulting in significant purchase commitments from the Southeast Asian country, following negotiations to avoid steeper US tariffs.

Indonesian goods entering the United States would face a 19 percent tariff, Trump said in a post on his Truth Social platform. This is significantly below a 32 percent level the president earlier threatened.

"As part of the Agreement, Indonesia has committed to purchasing US$15 Billion Dollars in US Energy, US$4.5 Billion Dollars in American Agricultural Products, and 50 Boeing Jets, many of them 777's," Trump wrote.

Boeing shares rose by 0.9 percent after the announcement.

In a separate post earlier on Tuesday, Trump touted the finalised pact as a "great deal, for everybody."

The Trump administration has been under pressure to wrap up trade pacts after promising a flurry of deals recently, as countries sought talks with Washington to avoid Trump's tariff plans.

But the US president has so far only unveiled other deals with Britain and Vietnam, alongside an agreement to temporarily lower tit-for-tat levies with China.

Last week, Trump renewed his threat of a 32 percent levy on Indonesian goods, saying in a letter to the country's leadership that this level would take effect August 1.

It remains unclear when the lower tariff level announced on Tuesday will take effect for Indonesia. The period over which its various purchases will take place was also not specified.

Trump said on social media that under the deal, which was finalised after he spoke with Indonesian President Prabowo Subianto, goods that have been trans-shipped to avoid higher duties will face steeper levies.

He separately told reporters that other deals are in the works including with India, while talks with the European Union are continuing.

Indonesia's former vice minister for foreign affairs Dino Patti Djalal told a Foreign Policy event on Tuesday that government insiders had indicated they were happy with the new deal.

Trump in April imposed a 10 percent tariff on almost all trading partners, while announcing plans to eventually hike this level for dozens of economies, including the EU and Indonesia.

But days before the steeper duties were due to take effect, he pushed the deadline back from July 9 to August 1. This marked his second postponement of the elevated levies.

Instead, since early last week, Trump has been sending letters to partners, setting out the tariff levels they would face come August.

So far, he has sent more than 20 such letters including to the EU, Japan, South Korea and Malaysia.

Canada and Mexico, both countries that were not originally targeted in Trump's "reciprocal" tariff push in April, also received similar documents outlining updated tariffs for their products.

But existing exemptions covering goods entering the United States under a North American trade pact are expected to remain in place, a US official earlier said. (AFP)