US Republican mega-donor and hard-line Zionist Sheldon Adelson has not decided yet which presidential candidate supports Israel the most and deserves his financial backing in election.

The casino owner, who together with his wife spent nearly $100 million in the 2012 presidential campaign cycle, is still weighing his options, according to more than half a dozen sources close to Adelson, The Hillreported on Sunday.

Adelson has expressed interest in Florida Senator Marco Rubio and his wife Miriam likes Texas Senator Ted Cruz, the sources say.

“The guy is cagey,” said a conservative leader with ties into the donor community who spoke with Adelson recently. “He said ‘I like Rubio,’ he did not say ‘I support him’… But he also said that his spouse feels more strongly about Cruz.

"At the end of the day, he wants somebody he can agree with on the issues,” said a source who speaks to Adelson regularly. “But winning is the most important criteria.”

He has also met several times with Jeb Bush's campaign and has been reassured that the former Florida governor will staunchly defend Israel, the subject the billionaire cares about most.

Adelson was listed by Forbes in June as having a fortune of $28 billion, making him the 18th richest person in the world.

He is a major contributor to Republican Party candidates, which has resulted in his gaining significant influence within the party.

Adelson, a Zionist Jew, has said his most important issue when considering which candidates to support in US elections is "the safety of Israel."

Adelson donated $1 million to a political action committee supporting Newt Gingrich, who was a Republican candidate for the presidential nomination in 2012.

Funded almost entirely by Adelson, the former speaker of the House of Representatives assaulted and nearly destroyed the ultimate GOP nominee, Mitt Romney.

Many conservatives believe the negative ads by Gingrich contributed to Romney’s loss to the incumbent candidate, President Barack Obama.

By Press TV