US President Donald Trump said he was "increasing tariffs on South Korean imports" in the US, related to cars, lumber and pharmaceuticals, up to 25%, Reuters reported.
At the same time, the head of state accused the "ally" legislature of "not complying with the country's trade agreement with Washington", the world agency specified.
"The South Korean legislature is not complying with the agreement with the United States", Trump wrote on social media.
"Because the South Korean legislature has not adopted our historic trade agreement, I am increasing the TARIFF for South Korea on cars, lumber, pharmaceuticals and all other reciprocal TARIFFS from 15% to 25%", the US president announced.
British Prime Minister Keir Starmer flies to China today for the first visit there by a British prime minister in 8 years since, his office confirmed, quoted by PA Media and DPA.
The last UK prime minister to visit China was Theresa May in 2018.
This week, the Labour Party leader will also visit Japan, 10 Downing Street said.
The visits will mark a significant moment in Starmer's efforts to build bridges with Beijing after the freezing of Sino-British relations in the final years of the previous government - the Conservative Rishi Sunak.
The visit also comes after Starmer's government approved controversial plans last week to build a huge new Chinese embassy in London. The loss will be the biggest for Beijing's diplomatic representation in Europe.
The British Prime Minister's delegation includes leading businessmen in the context of his desire to improve trade relations with the world power.