Despite the diplomatic breakthrough on the Korean Peninsula, the US says the administration isn't changing its conditions regarding talks with DPRK.

NIKKI HALEY US AMBASSADOR TO THE UN "No, I think stop testing is very important and for a significant amount of time, and then you go when you work towards the next step. This is going to be phases. This isn't going to happen overnight, as we've seen. But it's a dangerous situation."

Haley also said US President Donald Trump's tweet about having a bigger nuclear button than Kim Jong Un's has kept the DPRK leader "on his toes" and made clear the risks of a nuclear standoff. Meanwhile, the aircraft carrier USS Carl Vinson is en route to the Western Pacific. The US Navy says it's a "regularly scheduled deployment", but didn't reveal the scheduled arrival date and mission period. It remains unclear whether the flattop will join the annual South Korea-US drills to be staged after March.