Are ICTP and NORDITA international institutions (like CERN)?

[Suekdccia]

Are ICTP and NORDITA really international institutions about physics (like CERN) or are they actually an Italian and a Swedish organization respectively?

 

[Astronuc]

According to their website, ICTP is governed by UNESCO, IAEA, and Italy, and is a UNESCO Category 1 Institute.
https://www.ictp.it/about-ictp.aspx - see the bottom of the page.

Nordita has a governing Board, appointed jointly by the President/Vice-chancellor of the host universities KTH and Stockholm University, with one representative and one alternate member from each of the five Nordic countries, nominated by the respective research councils. The Chairman of the Board is nominated by the Joint Committee of the Nordic Natural Science Research Councils, NOS-N. The Nordita board nominates a Director, responsible for the day-to-day administration of the institute, who is appointed by the President/Vice-chancellor of KTH and Stockholm University.

Since Nordita is not a legal entity in its own right, the institute is administratively organized as an independent unit one of the two host universities, Stockholm University, reporting directly to the Vice-chancellor.

Funding
Until 2006, Nordita was funded by the five Nordic countries Denmark, Finland, Iceland, Norway and Sweden through the Nordic Council of Ministers.

Currently Nordita funding is shared between the http://norden.org/en/nordic-council-of-ministers, the Swedish Research Council, the two host universities KTH Royal Institute of Technology and Stockholm University, and Uppsala University.

https://www.nordita.org/aboutus/index.php

One could easily find this oneself with a little effort.