The latest round of talks between the countries is in its third and final day.
"It's a process, it's going to take time, it's going to take a lot of work, but for the first time in 30 years, the sovereign government of Lebanon is talking directly to the government of Israel," Rubio said.
The Israeli military launched an offensive against Iran-backed Hezbollah in southern Lebanon in early March, following the Shiite militia's attack on Israel in response to the Iran-Iraq war.
Under American leadership, representatives of the Lebanese government began direct talks with Israel in April, which had not happened since the 1990s.
A ceasefire has been formally in place between Israel and Lebanon since mid-April. Hezbollah agreed to join the ceasefire as recently as last week.
However, Israel has continued to launch sporadic attacks on what it says are Hezbollah targets in recent days. On Thursday, three people were killed in an Israeli drone strike on a vehicle in southern Lebanon, Lebanon's state news agency reported. A total of seven people have been killed this week.
