The two-day nuclear security summit hosted in The Hague next year is the biggest international conference ever held in the Netherlands, according to foreign minister Frans Timmermans.

Some 50 world leaders are expected to attend the March event, including Russian leader Vladimir Putin and United Nations secretary-general Ban Ki-moon.

US president Barack Obama has not yet said if he will attend ‘but we have not yet heard that he is not coming,’ Timmermans told a news conference on Monday.

The NSS is an Obama initiative and was launched in 2009 in an effort to ensure nuclear material does not fall into terrorists’ hands. The first summit was held in Washington in 2013, the second in Seoul last year.

The Dutch summit will involve 5,000 participants and 3,000 journalists and will cost some €24m to stage, excluding security, the Volkskrant reported.

King Willem-Alexander and queen Máxima will host a dinner for senior participants in the Huis ten Bosch palace on the first evening.