U.S. President Donald Trump speaks during a meeting with Austria's Chancellor Sebastian Kurz in the Oval Office at the White House in Washington on Wednesday (local time). Trump said North Korea's leader must make a "meaningful" gesture for the U.S. to lift sanctions on Pyongyang. Reuters-Yonhap

U.S. President Donald Trump said Wednesday (local time) that North Korea must take "meaningful" steps toward denuclearization to win sanctions relief from the United States.

Trump plans to meet North Korean leader Kim Jong-un in Hanoi, Vietnam, on Feb. 27 and 28 to flesh out an agreement they reached at last June's first summit in Singapore to dismantle the North's nuclear weapons program.

"We'll be meeting with Chairman Kim for two days and I think we'll accomplish a lot," Trump told reporters at a meeting with Austrian Chancellor Sebastian Kurz at the White House. "I don't think this will be the last meeting by any chance."

Washington has sought to persuade Pyongyang to dismantle its nuclear weapons and ballistic missile programs under the inspection of outside experts.

North Korea has in turn called for "corresponding measures," such as sanctions relief and a formal end to the 1950-53 Korean War.

"The sanctions are on in full, as you know," Trump said. "I haven't taken sanctions off. I'd love to be able to, but in order to do that, we have to do something that's meaningful on the other side."