U.S. President Donald Trump said on Wednesday he had received a letter from North Korean leader Kim Jong Un and expected to meet him again soon as part of the U.S. administration's efforts to press Pyongyang to give up its nuclear weapons program.

Speaking to reporters at the White House, Trump defended his negotiations with Kim and said he had never emphasized the speed of Pyongyang's denuclearization.

Kim vowed to work toward denuclearization of the Korean Peninsula when he met with Trump for the first time at a summit in Singapore in June, but there has been little concrete progress since.