<p>Nationally Determined Contributions (NDCs) under the Paris Agreement represent countries’ self-defined climate goals are required to be updated every five years. They serve as a key mechanism for tracking progress toward emission reduction targets, enhancing transparency, and identifying areas where international support is needed. Despite their role as a central governance instrument within the climate treaty, little is known about how countries respond to the pledge-and-review system in terms of meeting submission timelines. This study examines the factors associated with countries’ timely submission of the second-round NDCs. The analysis finds that countries with greater political stability and lower climate vulnerability are more likely to submit updated or new NDC 2.0s. In contrast, countries facing high climate vulnerability and political instability are less likely to do so, highlighting structural barriers to sustained climate engagement. These findings underscore the importance of strengthening capacity-building efforts to support vulnerable and politically unstable nations in implementing their NDCs, while calling for greater attention to the pledge-and-review process as the foundation for the Paris Agreement’s ambition mechanism.</p>