De facto embassy

A de facto embassy is an office or organisation that serves de facto as an embassy in the absence of normal or official diplomatic relations among countries (thus paradiplomacy); usually, to represent nations which lack full diplomatic recognition, regions or dependencies of countries, or territories over which sovereignty is disputed. In some cases, diplomatic immunity and extraterritoriality may be granted.

Alternatively, states which have broken off direct bilateral ties will be represented by an "interests section" of another embassy, belonging to a third country that has agreed to serve as a protecting power and is recognised by both states. When relations are exceptionally tense, such as during a war, the interests section is staffed by diplomats from the protecting power. For example, when Iraq and the U.S. broke diplomatic relations due to the Gulf War, Poland became the protecting power for the United States. The United States Interests Section of the Polish Embassy in Iraq was headed by a Polish diplomat.

However, if the host country agrees, an interests section may be staffed by diplomats from the sending country. From 1977 to 2015, the United States Interests Section in Havana was staffed by Americans, even though it was formally a section of the Swiss Embassy to Cuba. The last Political-Economic Section Chief of the U.S. Interests Section, Jeffrey DeLaurentis, became the first chargé d'affaires of the re-established Embassy.

Many countries maintain formal diplomatic relations with the People's Republic of China but operate unofficial "trade missions" or "representative offices" in Taipei to deal with Taiwan-related commercial and consular issues. Often, these delegations may forward visa applications to their nearest embassy or consulate rather than processing them locally.

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Wikipedia