Turkey has recognised the rebel Transitional National Council as the true representative of Libya's people.
Turkish Foreign Minister Ahmet Davutoglu said it was time for the Libyan leader Muammar Gaddafi to go.
Turkey has pledged a further $200m in aid for the rebels in addition to $100m announced last month.
In another development, the rebels have rejected an initiative by the African Union to sponsor talks between them and the government in Tripoli.
Rebel spokesman Abdel Hafiz Ghoga said: "We have rejected it. It did not include the departure of Gaddafi, his sons and his inner circle."
But TNC head Mustafa Abdul Jalil has conceded that Col Gaddafi is welcome to live out his retirement inside Libya as long as he gives up all power.
"As a peaceful solution, we offered that he can resign and order his soldiers to withdraw from their barracks and positions, and then he can decide either to stay in Libya or abroad," he told Reuters news agency.
"If he desires to stay in Libya, we will determine the place and it will be under international supervision. And there will be international supervision of all his movements."
Turkey's foreign minister met Mr Jalil in Benghazi, the rebels' main stronghold in eastern Libya, before addressing a news conference in the city.
"Public demand for reforms should be answered, Gaddafi should go and Libya shouldn't be divided," said Mr Davutoglu.
"I am here to express solidarity with the Libyan people. Their legitimate right should be realised, there should be a permanent solution to the crisis, which is possible only through a political solution based on the demands of the Libyan people.
"We see the Transitional National Council as the legitimate representative of the Libyan people to achieve their goals."
Correspondents say Mr Davutoglu's trip to Benghazi signals that Turkey - a key regional power and Nato member which initially opposed Western-led military action in support of the Libyan rebels - is throwing its weight behind the Libyan opposition.
Turkish companies were involved in construction projects worth billions of dollars in Libya before the outbreak of the anti-government uprising in February.
Meanwhile, the Russian government has said the Libyan crisis will be a key item on the agenda at discussions with Nato on Monday.
The talks, in the southern Russian resort town of Sochi, will include a meeting between Russian President Dmitry Medvedev and Nato Secretary General Anders Fogh Rasmussen.
Russia is a critic of the Nato military action in Libya.
South African President Jacob Zuma will also attend the meeting.
BBC News, Libya: Turkey recognises Transitional National Council, 3 July 2011