SEOUL (AP) -- The US ambassador to South Korea said Thursday he was surprised and pleased that North Korea did not give the US an unwelcome "Christmas gift" because of stalled nuclear disarmament talks, and that President Donald Trump is still confident it will denuclearize.

North Korea had warned that its "Christmas gift" to the US would depend on what action Washington took in the talks, leading to concerns that it might conduct a major weapons test. It has not conducted any such test, although the US did not meet a year-end deadline set by leader Kim Jong-un to make concessions.

"You can say that I personally was surprised. But I'm glad also ... there was no Christmas gift," Ambassador Harry Harris told reporters in Seoul. "Washington was ready for any eventuality, and we were all glad that there was no ICBM test or nuclear test."

He said both Trump and South Korean President Moon Jae-in "are keeping the door open to negotiations and hoping Kim Jong-un will walk through that door."

"So the ball is in his court," he said.

During their first summit in Singapore in 2018, Kim made a vague pledge to work toward complete denuclearization of the Korean Peninsula and the two leaders agreed to improve relations to build lasting peace. Their two subsequent summits and other lower-level meetings have not achieved much progress in fleshing out those agreements.

Harris said Trump believes Kim will live up to the Singapore pledge.

"President Trump ... is still confident that Kim Jong-un will meet the commitment that they both made together in Singapore,'' Harris said. "We should focus on President Trump's view that there is room for discussion here."

Prospects for a restart of diplomacy are unclear.

In a meeting of his ruling party late last month, Kim said he will not denuclearize if the US persists with its "hostile policy" toward his country. He also said he would soon unveil a new "strategic weapon" and no longer be bound by a weapons test moratorium that he announced at the start of his diplomacy with Trump. (AP)