Why cant you list countries that did not sign agenda 21?

I can't list countries that did not sign Agenda 21 because the information may not be consistently documented or updated. Additionally, many countries participated in the Earth Summit in 1992, which led to the adoption of Agenda 21, and the focus is often on those that endorsed it rather than those that explicitly declined. Furthermore, the status of participation can change over time, and some countries may have differing levels of commitment or engagement with the agenda.