WASHINGTON -- The United States will continue "patient" diplomacy with North Korea to make clear that the regime needs to return to denuclearization talks, a senior State Department official said Wednesday.

The official spoke to reporters on condition of anonymity to discuss last week's meetings involving the top diplomats of South Korea, the US and Japan. His remark suggests Washington is not willing to offer concessions to get Pyongyang back to the negotiation table.

"On North Korea -- slow, patient, steady diplomacy," the official said when asked about plans for future engagement with the North. "We're going to stick with this plan. It's working. We'll coordinate with allies and partners in the region to continue to make sure that that pressure is steady and insist that UN Security Council resolutions are enforced. That will continue to make clear to the North that they need to come out and negotiate and talk."

The two countries last held working-level talks in October to try to reach a deal on denuclearizing North Korea in exchange for US sanctions relief and security guarantees.

Since the talks ended without an agreement, North Korea has threatened to resume nuclear and long-range missile tests and declared that denuclearization is off the table.

"The president remains committed to making progress," the official said. "The Singapore summit commitments and diplomacy is the focus."

At their first summit in Singapore in June 2018, US President Donald Trump and North Korean leader Kim Jong-un agreed to work toward complete denuclearization of the Korean Peninsula, improve bilateral ties and build a permanent peace regime on the peninsula.

The two met twice more, but failed to make progress.

Asked to confirm that North Korean Foreign Minister Ri Yong-ho has been replaced by former army officer Ri Son-gwon, the official said he was aware of the reports but did not provide details.

"I don't have a lot of information on Ri being replaced by Ri," he said. "I don't have a lot of data on who he is or what he represents ... but the hope is that they'll understand the importance of having a conversation and talking about these things, as we agreed in the original Singapore agreement. So there's nothing to be gained by not talking. It's only to their benefit, so we encourage them to talk."

Meanwhile, on the ongoing defense cost-sharing negotiations between South Korea and the US, the official defended US Secretary of State Mike Pompeo and US Defense Secretary Mark Esper for publishing a joint op-ed in The Wall Street Journal last week to urge Seoul to pay more for the upkeep of American troops on the peninsula.

"The op-ed is showing that this is not just diplomatic or security. It's both," he said. "A look at all those things that the US presence for the last 70 years has brought especially following the Korean War, and just again noting the value to all of us, both sides in the alliance." (Yonhap)