The 20-year jail term handed down to an Iranian diplomat by a Belgian court for his role in a foiled bomb plot is illegal and a clear violation of international law, Iran’s Foreign Ministry spokesperson said on Thursday.

Assadolah Assadi, 49, who served as Iran’s envoy in Vienna, was given the maximum sentence on Thursday in Europe’s first trial of an Iranian official on terrorism charges since the Iranian revolution of 1979.

“As we have stated many times before, Assadolah Assadi’s detention, the judicial process and the recent sentencing are illegal and a clear violation of international law, especially the 1961 Vienna Convention,” said Iranian Foreign Ministry spokesman Saeed Khatibzadeh, according to Iran’s state-run TV.

Khatibzadeh said Iran “strongly condemns” the judgment, claiming that Belgium and other EU nations are influenced by the “hostile atmosphere of the terrorist group of hypocrites in Europe.”

Iran reserves the right to pursue all available legal and diplomatic channels to protect Assadi’s rights and hold accountable countries that have “violated their international obligations,” the spokesman said.

On Thursday Assadi was found guilty of planning to bomb a 2018 meeting of the National Council of Resistance of Iran, a Europe-based political coalition whose aim is to bring down the Iranian regime.