The EU foreign policy chief has had meetings in Lebanon at the start of a Middle East tour which will take him to Syria for the first time in two years.
Mr Solana goes on to Saudi Arabia and then a return to Syria
Javier Solana said his main aim in Beirut was to reinforce EU support for Lebanon engulfed in political crisis.
But he expressed optimism about talks between rival political forces.
EU officials say when Mr Solana goes on to Syria he will ask President Bashar al-Assad to take constructive steps in the Middle East, especially in Lebanon.
It will be Mr Solana's first trip to Syria since a two-year French veto on direct contact with the country - following the assassination of former PM Rafik Hariri - was lifted.
Syria has denied involvement in the killing. Its officials have been implicated in a UN-appointed enquiry.
Mr Solana's trip to Damascus is being preceded by a visit there by a senior American official, Assistant Secretary of State for Refugees and Migration Ellen Sauerbrey, following up last week's meeting in Iraq between the US and Syria.
In Beirut, Mr Solana met Lebanese Prime Minister Fouad Siniora and the speaker of parliament, Nabih Berri, for talks on the long political stalemate.
"I come out of the meeting more optimistic than when I went in," Mr Solana said after meeting the pro-Syrian Mr Berri.
He urged them to find a quick political solution ahead of a 28 March planned summit of Arab leaders.
Shortly after Mr Solana's departure, Mr Berri and the pro-Western parliament majority leader Saad Hariri held another round of talks - their third in five days.
Mr Solana promised he would speak "frankly" to Syrian leaders about upholding Lebanese independence, "a very important element of stability in the region".
Mr Solana left Beirut for Saudi Arabia, for a trip reflecting Riyadh's increasingly centre-stage diplomatic role in relation to the Palestinian-Israeli conflict.
Saudi Arabia recently brokered a unity agreement between the rival Palestinian factions Fatah and the ruling Hamas party.
Israel, its Western allies and a number of international bodies have boycotted the Hamas-led Palestinian government, demanding it renounce violence and sign up to past agreements with Israel.