Lifting of sanctions tweeted by Trump referred to what Treasury Department announced day earlier: Bloomberg

2019-03-27 3

U.S. President Donald Trump reportedly intended to remove sanctions imposed on two Chinese shipping companies accused of violating North Korea trade prohibitions,... which were announced last week by the Treasury Department.
While officials in his administration persuaded President Trump to back off,... he explained with a vague Tweet on Friday afternoon that he (quote) "ordered the withdrawal of additional large-scale sanctions against the North."
Citing government sources,... Bloomberg reports there were in fact no additional North Korea sanctions in the works at the time.
It also explained President Trump had not signed off on the specific sanctions before they were announced by the Treasury,... but had given the department discretion to decide sanctions as it saw fit.