The US imposed an additional tariff from Tuesday of 10% on all goods not covered by exemptions, a notice issued by US Customs and Border Protection (CBP) said, the rate initially announced by President Donald Trump on Friday rather than the 15% he promised a day later.

Reacting to the Supreme Court ruling that threw out his tariffs that had been justified on grounds of an emergency, Trump initially announced a new temporary global tariff of 10%. He said on Saturday he would increase it to 15%.

In a notice described as intended to "provide guidance regarding the February 20, 2026, Presidential Proclamation", CBP said that, aside from products specified as subject to exemptions, imports would "be subject to an additional ad valorem rate of 10%".

The move added to confusion surrounding US trade policy, with no explanation offered for why the lower rate had been used. The Financial Times quoted a White House official saying the increase up to 15% would come later. Reuters could not immediately confirm this.

Collection of the new tariffs began at midnight, while the collection of the tariffs annulled by the Supreme Court was halted.They had ranged from 10% to as much as 50%.

The Section 122 law allows the President to impose the new duties for up to 150 days on any and all countries to address "large and serious" balance-of-payments deficits and "fundamental international payments problems."

Trump's tariff order argued that a serious balance of payments deficit existed in the form of a $1.2-trillion annual US goods trade deficit and a current account deficit of 4% of GDP and a reversal of the US primary income surplus.

On Monday Trump warned countries against backing away from recently negotiated trade deals with the US, saying that if they did, he would hit them with much higher duties under different trade laws.

Japan said on Tuesday it had asked the United States to ensure its treatment under a new tariff regime would be as favourable as in an existing agreement. Both the EU and Britain have indicated they want to stick to deals already agreed.