DUBAI (Reuters) - Saudi Arabia has designated two senior officials of the Lebanese Hezbollah group as terrorists, accusing them of involvement in spreading "chaos and instability", state news agency SPA reported on Wednesday.

The agency identified one as Khalil Youssef Harb and said he was a military commander in charge of Hezbollah's activities in Yemen. SPA named the second as Mohammed Qabalan and said he had been convicted by an Egyptian court in absentia in 2010 for activities in the country.

The agency said the kingdom had imposed financial sanctions on the two, including freezing their assets and banning Saudis from any dealings with them.

Hezbollah could not immediately be reached for comment.

"As long as Hezbollah seeks to spread chaos and instability and carries out terrorist attacks and carries out criminal and illegal activity around the world, the Kingdom of Saudi Arabia will continue to designate activists and leaders and entities of Hezbollah and impose sanctions on them," a statement said.

The United States welcomed the Saudi move, saying Washington had also designated the two men in 2013 for overseeing "violent operations" in the Middle East.

"Today's step taken by Saudi Arabia reflects the close counter-terrorism and information-sharing cooperation we enjoy and look forward to extending further," said Adam Szubin, U.S. Treasury acting undersecretary for terrorism and financial intelligence.

The Saudi Interior Ministry in March last year designated several Islamist organizations based in the kingdom and abroad, including the Iranian-backed Hezbollah, as terrorist organizations.

Saudi Arabia has been leading a coalition of Arab states in air strikes on Houthis in Yemen, as part of a campaign to restore President Abd-Rabbu Mansour Hadi to power.

The kingdom is also a leading supporter of Sunni Muslim rebels trying to topple Syrian President Bashar al-Assad, while Hezbollah fighters are helping to shore up his forces against groups they call terrorist.

Hezbollah has repeatedly criticized Saudi Arabia over both its military operations in Yemen and its support for rebels in Syria.

(Reporting by Sami Aboudi and Reporting by Anna Yukhananov in Washington,; Editing by William Maclean and Andrew Roche)