President Milos Zeman will host the Presidents of Hungary, Poland and Slovakia, and senior NATO officials, at the Spanish Hall in Prague Castle, on Tuesday.

According to Hrad.cz, the four will be joined by Prime Minister Andrej Babis (ANO), Chamber Speaker Radek Vondracek (ANO) and Senate Chair Jaroslav Kubera (ODS) at a conference to celebrate the 20th anniversary of the accession of the countries to NATO (Slovakia’s 15th anniversary).