And most of the visitors' arrangements, from official audiences to dinner reservations, often must be made by the local embassy.
There may also be times when contact with your local American embassy or consulate is required.
On every trip to a foreign capital I made a habit of visiting the local embassy.
Visa regulations are always subject to change, so check at www.ukvisas.gov.uk or with your local British embassy before leaving home.
Check the local embassy's website for processing times and other information.
If you are outside the United States, contact your local embassy or consulate.
The list changes sometimes; check well ahead of travel with your local Mexican embassy or consulate.
But they can typically turn up at their local Chinese embassy and receive a visa in a day or less.
The group has a list of actions which it says bloggers can take, including writing to local Iranian embassies.
Normal federal regulations required a visiting agent to check in with the local embassy, but she would do no such thing.