The boundary became an international frontier in 1991 following the dissolution of the Soviet Union and the independence of its constituent republics. Tensions has already become apparent with the Krgyz-Uzbek riots in the city of Osh in 1990. In 1999/2000 Uzbekistan began unilaterally demarcating and mining sections of the border, citing the threat of cross-border terrorism. A 2001 agreement to potentially demarcate sections of the border and create land-swaps connecting their respective enclaves to the ‘mainland’ was poorly received in Kyrgyzstan and the agreement was never ratified, leading to continued tension along the border at this time. In more recent years relations have improved and a border agreement was signed in 2018 delimiting much of the boundary; discussions over the status of the enclaves is currently ongoing.