King Abdullah of Jordan says the Syrian president Bashar al-Assad should resign in the interests of his country.
The Jordanian king is the first Arab leader to call on President Assad to go since Syria began its violent suppression of anti-government protests.
He says President Assad should launch a dialogue with his opponents to effect an orderly transition and ensure his successors can bring about change.
Syria is currently suspended from the Arab League because of its violent response to anti-government demonstrations.
King Abdullah's comments, in a BBC interview, came after the Syrian foreign minister Walid al-Moualem denounced his country's suspension from the Arab League.
"If I were in his shoes, I would step down. If it was me I would step down and make sure whoever comes behind me has the ability to change the status quo that we're seeing, and I don't think the system allows for that," he says.
He says President Assad should "create an ability to reach out and start a new phase of Syrian political life."