Solana told Spain's El Pais daily that he hoped the UN-mandated disarmament of Hezbollah's militia in southern Lebanon would take place "in the most poitical manner possible" so that the radical Shiite group "becomes a political force in the life of a normalized Lebanon."
"But the relations between Hezbollah and Iran will make this process difficult," said the European Union's top diplomat.
Unlike the United States, the EU does not classified Hezbollah as a terrorist organization.
On Monday, Hezbollah chief Hassan Nasrallah said the disarmament of his fighters could not be done "in haste... or by intimidation, pressure or provocation," and that it could only occur "through dialogue between Lebanese."
Solana also said that the seven-fold build up of the multinational UN Interim Force in Lebanon (UNIFIL) should start by the beginning of next week at the latest. The deployment "will be a question of weeks," he said.
UN Security Council Resolution 1701, unanimously adopted Friday, mandates that UNIFIL will swell from its current level of 1,990 troops to 15,000.
"Nobody won this war, because a UN Security Council resolution intervened before there was a victor," Solana said.