South Korean President Moon Jae-in vowed to prevent war at all costs and told the United States that it would need Seoul’s permission to attack North Korea, Reuters reported. The statement put South Korea at odds with the US, its long-time ally, given that President Donald Trump and his team have taken a combative approach towards Pyongyang.

“The government, putting everything on the line, will block war by all means,” Moon said in a televised speech on Tuesday to mark the 72nd anniversary of the country’s liberation from Japanese occupation.

He also warned the North Korean government of a dark future and international isolation if it continues on its current path. “Without international cooperation and co-existence, economic development is impossible,” Moon said, urging the North to come to the dialogue table.

On Monday, Moon had told a United States official that America must respond in a calm and responsible manner to find a diplomatic situation for the crisis. He had also urged North Korea to stop its hostile rhetoric, which was only worsening the situation.

Tensions between North Korea and the United States have been rising over the last few weeks. North Korea had threatened to strike Guam with medium-to-long-range strategic ballistic missiles. A Korean People’s Army spokesperson had said that the military was only waiting for its leader Kim Jong-Un to make a decision on the plan. North Korea later said it was going to hold off on the plan.

On August 9, Trump had warned Pyongyang that any threat to the country would be met with “fire and fury like the world has never seen”. He had also warned North Korea that it would “truly regret” if it were to act against any US territory or allies.