The bill call for Estonia to join the center, which was established with the signing of a memorandum in Helsinki last week, by June 1 at the latest, spokespeople for the party said.

Reform MP Eerik-Niiles Kross, a member of the Foreign Affairs Committee of the Riigikogu, said that belonging to the Western realm of values and membership of and intense activity in NATO and the EU are the cornerstones of Estonia's security.

"The government has said that by not joining the center, they didn't wish to send a political signal," said Kross. "Unfortunately, Estonia's incomprehensible passiveness on a subject so important for our security works as a worrying signal. I hope that the government will reconsider and Estonia will join the European Centre of Excellence for Countering Hybrid Threats in the near future."

The Estonian MP added that hybrid threats must be considered as serious as conventinal military threats.

Nine NATO allies and EU members convened in Helsinki on April 11 to formally agree on establishing the European Centre of Excellence for Countering Hybrid Threats. At a ceremony attended by Finnish Minister of Foreign Affairs Timo Soini, NATO and EU officials hailed the signing of a memorandom of understanding for the center, which will open later this year.

Nine nations signed the memorandum, including Finland, France, Germany, Latvia, Lithuania, Poland, Sweden, the U.K. and the U.S. Norway and Spain have pledged to join it in the near future. While not signatories themselves, NATO and the EU will be actively involved in the center's activity.

Other centers of excellence already contribute to NATO's efforts to counter hybrid threats, including the Strategic Communications Centre of Excellence in Riga and the Cooperative Cyber Defence Centre of Excellence (CCD COE) in Tallinn. Centers of excellence are international research centers which are nationally or multinationally funded and staffed. While they are not NATO bodies, the centers work alongside and contribute knowledge and expertise to the alliance.