Miroslav Lajcak, Deputy Prime Minister and Minister of Foreign Affairs of Slovakia (left)
and Lassina Zerbo, Executive Secretary of the CTBTO

Cooperation agreement with Slovakia on OSI activities

Miroslav Lajcak, Deputy Prime Minister and Minister of Foreign Affairs of Slovakia (left) and Executive Secretary Lassina Zerbo

Miroslav Lajcak, Deputy Prime Minister and Minister of Foreign Affairs of Slovakia and CTBTO Executive Secretary Lassina Zerbo have signed an “Agreement on Mutual Cooperation for Training and Exercise Activities of the Commission related to On-Site Inspections.”


Lajcak and Zerbo discussed deepening the cooperation between Slovakia and the CTBTO, including in the framework of the events marking the 20th anniversary of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) in 2016 and regarding the storage of the organisation’s on-site inspection equipment in light of Slovakia’s proximity to the CTBTO’s headquarters in Vienna.

2009 Noble Gas Field Operations Test near Stupava, Slovakia.
SAUNA noble gas sampler used in the field operations test.

On-site inspections (OSIs) are the final verification measure under the Comprehensive Nuclear-Test-Ban Treaty (CTBT). They involve an inspection team of up to 40 inspectors searching on site for signs of a nuclear explosion, using up to 17 different OSI techniques. OSIs will be possible once the CTBT has entered into force. The CTBTO and its Member States conducted a large-scale OSI exercise, the Integrated Field Exercise 2014 last year in Jordan.

Slovakia has already hosted several OSI exercise and training activities, including field tests of seismic aftershock equipment in 2001 and a noble gas field operations test (see article in CTBTO Spectrum - PDF) in 2009.


The present agreement provides a comprehensive political, legal and administrative framework for future OSI activities hosted by Slovakia. This includes for example providing suitable sites and support for OSI training, exercises and equipment tests. The designated authority on the Slovak side is the Nuclear Regulatory Authority of the Slovak Republic.

Slovakia, like all countries of the European Union, has signed and ratified the CTBT. Its ratification in March 1998 was one of the first worldwide. Through voluntary contributions adopted by the European Union, Slovakia has also made substantial voluntary contributions in support of the CTBTO’s work in areas such as training, verification regime enhancement and technical assistance to third countries.