North Korean leader Kim Jong Un criticized the construction sector for failing to modernize and allowing delays in a letter to a builders conference that kicked off Tuesday in Pyongyang, according to state media, after high-profile projects missed deadlines last year.

Kim demanded drastic improvements to all aspects of the construction industry as he called for “simultaneous” building projects across all rural parts of the country, the Korean Central News Agency (KCNA) reported Wednesday.

The “2nd Great Workshop for Officials in the Field of Construction” will continue this week, the report said. Kim did not attend the first day,