President Donald Trump will visit South Korea next month amid questions about his stalled nuclear talks with Kim Jong Un.

The White House said Wednesday Trump would make the stop as part of a trip to Asia to attend the G20 summit in Japan.

In South Korea, Trump will meet with his counterpart Moon Jae-in, who has encouraged his talks with Kim in an effort to tamp down tensions on the Korean peninsula.

"President Trump and President Moon will continue their close coordination on efforts to achieve the final, fully verified denuclearization of the Democratic People's Republic of Korea," the White House said. "The two leaders will also discuss ways to strengthen the United States-Republic of Korea alliance and the friendship between our two peoples."

Trump's second summit with Kim collapsed in February after the North insisted sanctions be lifted on the country. The US, which has prodded Pyongyang to abandon its nuclear program to little avail, balked at the demand.

Since then, North Korea has resumed tests of short-range missiles.

Trump said last week that "nobody's happy about" the new tests, but insisted his relationship with Kim would persist.

"The relationship continues, but we'll see what happens," Trump said. "They want to negotiate, they're talking about negotiating, but I don't think they're ready to negotiate."