Sweden has especially angered Türkiye by refusing to extradite dozens of suspects that President Recep Tayyip Erdoğan links to a failed 2016 coup attempt and decades-long terrorism in the country.
The Nordic nation has had close ties with NATO ever since joining the Partnership for Peace programme in the 1990s, but as a non-member, it is not covered by the security guarantees of NATO's Article 5 on collective defence.