Hariri, who is expected for a two-day visit in Madrid on Thursday, said Lebanon was in favour of a "Middle East without" which he said "includes Israel" and not only Iran.
As Hariri prepares to make his second visit to Syria since taking office in November, he also said closer ties with Damascus were key to counter an "Israeli threat".
"Stronger ties with Syria mean there is a firmer position toward Israel," Hariri said. He also accused the media of under-reporting Israeli "atrocities" toward the Palestinians.
While paedophile priests in the Roman Catholic Church were given "extensive media coverage" amid "attacks against the Vatican", "atrocities committed by Israel against Palestinians" go practically unreported, said Hariri, who is a Muslim. For Israel "war is always an option", he added.