I personally always thought the joint exercises would be restarted in time to execute Key Resolve 2019 because I never believed the Kim regime was were serious about real denuclearization:
The U.S. military will move ahead with all future military exercises on the Korean Peninsula, Defense Secretary James N. Mattis said Tuesday, suggesting that America’s brief suspension of the drills as a show of “good faith” toward North Korea has not paid dividends in the struggling denuclearization talks with Pyongyang.
“We have no plans at this time to suspend any more exercises,” Mr. Mattis told reporters at the Pentagon, less than three months after President Trump labeled the U.S.-South Korean drills “provocative” and ordered them temporarily halted following his unprecedented face-to-face meeting with North Korean leader Kim Jong-un.
Mr. Mattis made the announcement at a rare press conference with Chairman of the Joint Chiefs of Staff, Marine Gen. Joseph F. Dunford, during which the two also weighed in on a range of other topics, including efforts to stamp out the Islamic State in Iraq and Syria and the U.S. role in battling Iran-backed rebels in Yemen. [Washington Times via a reader tip]
You can read more at the link, but supposedly the President received a hostile letter from the Butcher of the Cheonan, Kim Yong-chol that caused this announcement:
After the announcement it appears the ROK government may want to play delay games with restarting the joint exercises:
Resumption or suspension of joint military drills between South Korea and the United States is subject to discussions between the allies, an official from Seoul’s presidential office Cheong Wa Dae said Wednesday.
“As of now, the issue has not been discussed between South Korea and the United States,” Cheong Wa Dae spokesman Kim Eui-kyeom told a daily press briefing. (……)
“It is an issue that should be discussed and decided by South Korea and the U.S. while reviewing the progress in the denuclearization of North Korea,” the Cheong Wa Dae official said. [Yonhap]
I expect that the Moon administration will come out of his upcoming summit with Kim Jong-il offering some minor concession to entice the Trump administration to believe the Kim regime is serious about denuclearization. Regardless I would be surprised if Key Resolve 2019 does not happen. I guess we will see what happens.