State Department spokesman Mark Toner said that Hezbollah is still playing a major role in destabilizing the region, which incites terrorism.
The six-member Gulf Cooperation Council (GCC) named Hezbollah a terrorist organization on Wednesday (March 2), opening up the possibility of further sanctions against the Iran-allied group that wields influence in Lebanon and fights in Syria.
The Sunni Muslim dominated council - representing Saudi Arabia, the UAE, Bahrain, Kuwait, Oman and Qatar - already imposed sanctions on the Shi'ite Muslim group in 2013 after it entered Syria's war in support of President Bashar al-Assad.
In Wednesday's announcement, GCC Secretary-General Abdullatif al-Zayani said the council would now "take the necessary measures to implement its decision ... based on anti-terrorism laws applied in the GCC and similar international laws".
Zayani did not specify what action might follow, but Saudi Arabia, the biggest power in the grouping, last week said it had blacklisted four companies and three Lebanese men for having links to Hezbollah.
Zayani accused Hezbollah of committing "hostile acts" against GCC states, including recruiting young men to carry out "terrorist attacks, smuggling weapons and explosives, stirring up sedition and incitement to chaos and violence".