かたがた is a highly formal expression meaning “while” or “for the purpose of,” used when one action is undertaken alongside an additional related purpose or action. It commonly follows a noun describing the primary purpose, such as an expression of thanks, a greeting, or a report. The accompanying action is usually a visit or another purposeful activity, and the two actions are closely connected rather than unrelated. It is especially common in formal writing, official correspondence, and ceremonious speech.