Saudi Arabia on Tuesday welcomed Britain's decision to outlaw the political wing of Lebanon's Hezbollah movement, describing it as an "important and constructive" step.
Britain announced on February 25 it would seek to make membership of the Shiite movement or inviting support for it a crime.
The decision followed outrage over the display of the Hezbollah flag, which features a Kalashnikov assault rifle, at pro-Palestinian demonstrations in London.
"Categorising the (Hezbollah) militia, which is backed by Iran, as a terrorist organisation is an important and constructive step in combatting terrorism around the world," said a foreign ministry source, according to the official Saudi Press Agency.
"Britain's decision is in line with the decision Saudi Arabia has taken towards the terrorist party, both politically and militarily."
London's move was welcomed by other foes of Iran, Hezbollah's key supporter, including the United States and Israel.
Hezbollah meanwhile said Britain had "insulted the sentiments and the will of the Lebanese".
In 2016, the Gulf Cooperation Council -- which includes regional powerhouse Saudi Arabia, Bahrain, Kuwait, Oman, Qatar and the United Arab Emirates -- designated Hezbollah a "terrorist" organisation.
Hezbollah was established in 1982 during Lebanon's civil war and is now a major political party in the country, holding three cabinet posts.
Britain blacklisted Hezbollah's military wing in 2008 but had until now made no move against its political wing.
However, British Foreign Secretary Jeremy Hunt said last Monday that any distinction between its military and political wings "does not exist".
The US designated Hezbollah a foreign terrorist organisation in 1997.