The Arab League has declared Lebanese Shiite militia Hezbollah a terrorist organisation.

The US, Australia, Canada and the EU had blacklisted Hezbollah, a Shia political organisation with an armed wing, but the move by the Arab League gains significance in the backdrop of ongoing sectarian wars in Syria, Yemen and Iraq.

Iraq and Lebanon were the only Arab League members that disagreed with the decision, which was actively pushed by Saudi Arabia.

"The Arab League foreign minister's committee has decided on Friday to consider Hezbollah a terrorist organization," a statement issued after an Arab League meeting in Egypt said.

The Hezbollah militia is actively supporting embattled Syrian President Bashar al-Assad. Hezbollah is also one of the toughest regional adversaries of Israel and has close ties with Shiite Iran.

Lebanese authorities said they expressed reservations about the decision to blacklist Hezbollah, which holds key influence in the country.

"We voiced reservations because the resolution was not in line with the Arab anti-terror treaty ... Hezbollah enjoys wide representation in Lebanon and it is a main component in the country," Lebanon's Foreign Minister Gebran Bassil said in a Twitter post.

Iraqi authorities, who rely on Shiite militia in their battle against Sunni terror outfit Islamic State, also recorded disagreement with the decision.

"In his speech (the minister) said that Hashd Shaabi and Hezbollah had preserved the dignity of the Arabs and those who call them terrorists are the terrorists," an Iraqi foreign ministry source said, according to Reuters.

After the Arab league declaration, Saudi Arabia toughened its stance on Hezbollah.

"We will deal with Hezbollah as we deal with any terrorist organization. Saudi Arabia and the Gulf countries have begun preparing measures it will take against that terrorist party and they will be announced at the right time," Saudi Arabia's ambassador to Egypt Ahmed Kattan said on Al-Arabiya television.

The Arab League meeting also came down heavily on Iran saying Tehran was interfering in the affairs of Bahrain, a Shiite majority state ruled by Sunni Arabs.