A chargé d'affaires is the lowest of the four classes of heads of mission recognized under Article 14 of the 1961 Vienna Convention on Diplomatic Relations, ranking below ambassadors, nuncios, and ministers/envoys. Two distinct forms exist. A chargé d'affaires en pied (or en titre) is permanently accredited as head of mission, with credentials presented by the sending state's foreign minister to the receiving state's foreign minister rather than head of state to head of state. A chargé d'affaires ad interim (often abbreviated a.i.) is a temporary stand-in, typically the deputy chief of mission, who assumes leadership when the ambassador is absent, recalled, or the post is vacant.
States downgrade representation to chargé level as a calibrated diplomatic signal short of a full break in relations. This avoids the rupture of expelling all diplomats while clearly registering displeasure. The chargé retains full diplomatic immunities under the Vienna Convention but the symbolic weight of the bilateral relationship is reduced, since no ambassador is exchanged.
Functionally, a chargé d'affaires performs the same duties as an ambassador: representing the sending state, negotiating, protecting nationals, reporting, and promoting bilateral ties. The distinction is primarily one of rank, precedence, and political symbolism. Within the diplomatic corps of a capital, chargés follow ambassadors in the order of precedence regardless of length of service.
The role is also common during transitions between confirmed ambassadors, which can stretch for months or years due to domestic political delays in the sending state (a frequent occurrence with U.S. ambassadorial confirmations in the Senate). In such cases, the mission continues to operate normally under the chargé, though host governments often interpret prolonged vacancies as a downgrading of attention to the relationship.
Example
After the 2021 storming of the U.S. Capitol fallout and subsequent disputes, several U.S. embassies operated under a chargé d'affaires ad interim while Senate confirmations for ambassadors stalled.