SEOUL, South Korea: South Korean President Lee Jae Myung says that a strong alliance with the United States is essential for the country's national security.

His comments came after U.S. President Donald Trump suddenly ordered a "substantial reduction" in joint military exercises, leaving many South Koreans confused and worried.

Trump made the unexpected announcement in a social media post shortly before U.S. and South Korean troops began the annual Ulchi Freedom Shield exercises on August 17. The drills are mainly intended to improve the two countries' readiness to respond to threats from North Korea.

Trump said his decision was linked to his good relationship with North Korean leader Kim Jong Un. He also referred to South Korea's decision not to take part in the U.S. war against Iran.

The decision appeared to have been made without consulting South Korea. It was seen as an attempt to reach out to Kim and raised fresh concerns about the reliability of the U.S.-South Korean alliance, which was created during the conflict of the 1950-53 Korean War.

A reduction in the U.S. defense commitment could affect South Korea's national security because the country does not have nuclear weapons. Instead, it relies on protection under the U.S. nuclear umbrella, which promises a major American military response if nuclear-armed North Korea attacks its ally.

The United States has about 28,500 troops stationed in South Korea.

Trust in the United States has already weakened among many South Koreans because of Trump's tariff war and an immigration raid in Georgia last year. Hundreds of South Korean workers were detained during that operation.

South Korea's Hankook Ilbo newspaper said in an editorial on August 18 that Trump's announcement showed serious problems in the alliance and was increasing public anxiety. The newspaper also criticized the United States for appearing to treat North Korea with more respect than its ally South Korea.

At a regular Cabinet meeting, President Lee emphasized the importance of maintaining a strong military alliance with the United States. He said South Korea's national security would be stronger if the alliance remained solid.

Lee, a liberal leader who has called for South Korea to develop a stronger, more self-reliant defense system, also said that building up the country's own capabilities would increase its importance and value as a U.S. ally.

It was not immediately clear which parts of the 11-day South Korea-U.S. military exercises would be reduced.

The South Korean and U.S. militaries had earlier said that this year's exercises would be similar in size to previous years. They also planned to include lessons from recent conflicts, including North Korea's military experience on the Russia-Ukraine battlefield.

Both countries have said the exercises are defensive.

North Korea's Foreign Ministry accused South Korea and the United States of planning more provocative military exercises this year. It also warned that North Korea would respond by developing "a new level of a deterrent."

Kim Jong Un has refused to hold talks with the United States or South Korea since his earlier high-profile diplomacy with Trump broke down in 2019.

Experts said Kim was unlikely to accept Trump's latest attempt to reach out or return to negotiations soon unless Washington offered him bigger concessions.

On August 17, President Lee's office said it hoped the "friendly relationship" between Trump and Kim could lead to "meaningful dialogue" between the United States and North Korea and help promote peace on the Korean Peninsula.