Secretary of State Mike Pompeo says the U.S. would like to see a quick dismantlement of North Korea's nuclear weapons program but will not commit to a specific timeline.

Pompeo made the remarks in a news conference at the State Department on Wednesday ahead of departing for his fourth trip to Pyongyang on Sunday to meet with North Korean leader Kim Jong-un.

Pompeo told reporters that the previously stated goal of getting North Korea to abandon its nuclear weapons by the end of President Donald Trump's first term in January 2021 was not his comment. He said that deadline was set by the leaders of the two Koreas during their summit in Pyongyang and he just repeated it. 

Pompeo also expressed hope for his upcoming trip to Pyongyang, saying that he is "very happy" to be going back to make progress on a denuclearization agreement reached by the leaders of the U.S. and North Korea at their historic first summit in Singapore in June.

He said he is optimistic that his trip will lead to better understandings, deeper progress and a plan forward, not only for a second summit between the two leaders, but for efforts to build a pathway for denuclearization.