Later, at a luncheon attended by Siniora and Berri, Sarkozy stressed his country's support for Sleiman and Lebanese national unity.
Sleiman had "a great responsibility to drive this national reconciliation forward", he said.
"It is essential that all Lebanese political forces display their commitment to dialogue."
Sarkozy said that "once the institutions have stabilised, [Lebanon] must address the reconstruction of the state and the economy's dynamism to open up to reforms".
For his part, Suleiman said the "Doha agreement, in which France took part, has regenerated long-awaited and desired political stability".
He said that Lebanon is reforming its constitutional, judicial and other institutions in order to regain its role in the world.
Sleiman stressed Lebanon's commitment to fight "terrorism and all forms of extremism".
He said that any internal disagreement will be resolved through dialogue.
Sarkozy said France remained "committed to strengthening the capacities of the Lebanese army within the framework of a national defence strategy to be established through sincere dialogue ... that can no longer be delayed".
Sarkozy's office said France would provide training to the Lebanese army as part of its economic assistance programme.
A planned visit by the delegation to the French contingent of the United Nations Interim Force in Lebanon was cancelled, however, to keep the visit "a purely political" one, according to the Elysee.
Instead, Morin was to visit the French contingent of 1,800 soldiers, which is the second largest contingent in the south Lebanon-based peacekeeping force.
On a related issue, Sarkozy has indicated "a new page may be opening" in relations with Damascus that Paris suspended during the crisis.
A source close to his office said two senior envoys would soon visit Syria.
In an interview published on Friday in Lebanese dailies, Sarkozy recalled Paris had said it "would resume contacts with Syria only when positive, concrete developments occurred in Lebanon with a view to getting out of the crisis.
"One has to concede that the Doha accord, the election of President Sleiman and the return of Fouad Siniora as prime minister are such developments," he said.
"I have drawn the conclusions and I have called [Syrian President] Bashar al-Assad to tell him of my desire to see the carrying out of the accord continue."
Show of support
Earlier, Zeina Khodr, Al Jazeera's correspondent in Beirut, said: "Sarkozy's visit is really a show if support for Lebanon, the Lebanese people and the newly elected president."
Sarkozy was unlikely to unveil any strategy to help Lebanese leaders form a new cabinet, she said.
"Sarkozy is not really expected to take any practical measures to help Lebanon's leaders form a national unity government," Khodr said, "but he is here to give his blessing to the agreeement reached in [the Qatari capital] Doha which ended the political crisis."