Jordanian security forces claimed to have foiled an Iranian terrorist plot yesterday after arresting a man armed with 45kg of explosives.

Khaled al-Rubia, who holds Norwegian and Jordanian citizenship, is accused of being an operative of Iran’s elite al-Quds force and was arrested two weeks ago in the northern city of Jerash. He is said to have entered Jordan from Syria, where Iran is a significant player in the conflict against rebels seeking to overthrow President Assad.

A state security court in Jordan held its first hearing yesterday and issued a gagging order in the case.

The arrest comes as world powers are finalising a deal with Tehran, offering to lift economic sanctions in exchange for Iran curbing its nuclear ambitions.

Washington’s allies in the Middle East, from Israel to the Gulf states, are sceptical and accuse Iran of stoking conflicts across the region. In Syria, both Iranian militias and Hezbollah fightersbacked by Tehran are helping to prop up the Assad regime.

Saudi Arabia is embroiled in a conflict in Yemen against Shia rebels seen as a proxy Iranian force. Riyadh has accused Iran of fomenting strife among its minority Shia population and undermining the Sunni rulers of Bahrain.

Jordan, which is among the Arab nations arming and training Syrian rebels to fight the Assad regime, would seem to be an obvious target for Iran. Jordanian-backed groups are fighting in southern Syria against regime forces supported by Iranian-backed militias.

News of the plot came a day before the latest deadline in talks between Iran and the international community. The previous deadline of June 30 was extended last week until today, although there was talk yesterday of it being pushed back again until July 9. Foreign ministers from six countries, including Britain and America, have gathered in Vienna for a final push towards a deal.

Diplomats said yesterday that hopes of a swift resolution were fading because the Iranians were demanding that an arms embargo to be lifted at the same time as other United Nations sanctions are removed.

Iranian officials want sanctions on its ballistic missile programme lifted, claiming that it has no link with the conflict over Iran’s nuclear programme.

“There’s no appetite for that on our part,” a western official told Reuters.

John Kerry, the US secretary of state, said on Sunday that a deal was possible this week if Iran made “hard choices” but insisted that his side was ready to walk away if the terms of the deal were not satisfactory to Washington.

Both President Obama and his Iranian counterpart, Hassan Rouhani, face strong opposition to a deal from hardliners at home.