The Ministry of Foreign Affairs is maintaining its travel advice of 14 March cautioning against non-essential travel to all countries. The reason is the increased spread of the coronavirus internationally and the unpredictable and difficult situation faced by many travellers. This travel advice will remain in effect until further notice. More information about the corona situation from the Norwegian government can be found here.
Information about staying in Norway, entering Norway and visas for foreign nationals, including EU/EEA nationals, is available on the website of the Norwegian Directorate of Immigration (UDI).
The Norwegian Directorate of Immigration (UDI) has gathered the most frequently asked questions and answers about the corona situation that apply to EU/EEA nationals (this includes Dutch citizens) on a special web-page which is constantly updated here.