For a long research stay in France (at least one month) of a Vietnamese colleague, the IRL will cover the cost of transport but will ask the host laboratory to contribute to the cost of accommodation. It is therefore important to get in touch with the host laboratory, the IRL can help with these formalities.
For a long research stay in Vietnam (at least one month of a French colleague, it is important to anticipate this request, especially for teacher-researchers who need to free themselves from their teaching duties. To this end, the CNRS offers “delegations” of 6 months or 1 year, during which the teacher-researcher is freed from these duties. Requests for delegations are made in the autumn of the previous academic year, so it’s important to plan ahead.