WASHINGTON • US President Donald Trump has responded to North Korean leader Kim Jong Un's latest threats by saying that he has a "much bigger and more powerful" nuclear button.

Mr Trump's remark on Twitter came after Mr Kim warned the US on Monday that the nuclear button "is always on my desk", even as he proposed talks with South Korea to ease tensions.

The North Korean leader called his nuclear deterrent "irreversible" and, claimed it would prevent Mr Trump from starting a war.

"Will someone from his depleted and food-starved regime please inform him that I too have a nuclear button, but it is a much bigger and more powerful one than his, and my button works!" Mr Trump wrote on Twitter on Tuesday night.

Mr Trump's combative response to a statement made the day before by Mr Kim raised the temperature in the brewing confrontation between the United States and North Korea, even as American allies in South Korea were moving to open talks with Pyongyang.

The contrast between Mr Trump's language and the peace overture by South Korea highlighted the growing rift between two long-time allies. US Ambassador to the United Nations Nikki Haley dismissed the proposed dialogue between the Koreas as a "band-aid", warning that Washington would never accept a nuclear-armed Pyongyang.

The President's tone also generated a mix of scorn and alarm among lawmakers, diplomats and national security experts, who called it juvenile and frightening for a President handling a foreign policy challenge with world-wrecking consequences.

Mr Trump, who has disdained the prospects of negotiating with North Korea, said earlier in the day that the possible talks between the two governments on the peninsula resulted from sanctions imposed by the United States and the international community.

"Perhaps that is good news, perhaps not - we will see!" he wrote on Tuesday morning.

BLOOMBERG, NYTIMES