Just for clarity:
When the ICSID (International Centre for Settlement of Investment Disputes) publishes a statement like "The Respondent files a request to address the objections to jurisdiction as a preliminary question," it means that the Respondent (the party being sued in an arbitration case) is requesting that the tribunal first determine whether it has the authority (jurisdiction) to hear the case before proceeding with any other matters.
In other words, the Respondent is raising an issue about the tribunal's jurisdiction—whether the case is one that the tribunal is legally allowed to adjudicate—before moving on to the substantive issues in the dispute (such as the merits of the claim or the details of the investment dispute). This is often called a "preliminary objection" or "preliminary jurisdictional question".
By requesting this, the Respondent wants to ensure that the arbitration process should not even continue if the tribunal finds that it does not have the proper jurisdiction to hear the case in the first place. If the tribunal finds that it does not have jurisdiction, the case will be dismissed without addressing the underlying issues.
So, the statement essentially signals that there is a challenge to the tribunal’s authority to proceed, and that the Respondent wants that issue resolved early in the process.