On 21 March 2018, Kosovo's Assembly ratified the border agreement with Montenegro. The European Union set ratification as a condition before it would grant Kosovo nationals visa-free access to the pass-port free Schengen area. 8 September, Serbia’s President visited North Kosovo’s Gazivode Lake, an important source of Kosovo’s water. The following day, his planned visit to the majority-Serb village Banje was cancelled by the Kosovo government after Kosovo Albanian protestors put up barricades at the village’s entrance. 29 Sept, Kosovo’s President visited Gazivode Lake. Serbia accused Kosovo police of seizing control of the lake and briefly detaining workers and Kosovo said police were there to provide security for the visit and nobody was detained. A Kosovo Serbian representative said Serbia was putting its military as well as police under high alert as a result. 20 November The international police agency (INTERPOL), rejected Kosovo's membership. On 21 November, Kosovo imposed an import tax on Serbian and Bosnia Herzogovina goods. Kosovo said the tariff would be lifted when Serbia recognizes its sovereignty and stops blocking it from joining international organizations and Serbia said it will not participate in further dialogue until the measure is lifted.