U.S. Secretary of State John Kerry made an unannounced visit to Tunisia Tuesday to praise progress in the country where the Arab Spring began three years ago.

Kerry met in Tunis with President Moncef Marzouki, telling him the United States is "very impressed by the steps that you have been taking, by the rational thoughtful approach to the transition."

Kerry said Tunisia's new constitution, which was ratified in January, can serve as a model for others in the region. He described the document as "rooted in democratic principles -- equality, freedom, security, economic opportunity, and the rule of law."

Kerry was expected to meet with other Tunisian officials during his brief visit.

Tunisia's new constitution sets out to make the country a democracy not based on Islamic law. But some government opponents say the constitution does not do enough to protect women's rights.

U.N. Secretary-General Ban Ki-moon commended Tunisia on the new constitution, saying last month he believes the country can be a "model to other peoples seeking reforms."

Kerry traveled to Tunisia from the United Arab Emirates, where he held talks about the situation in Syria, Iran's nuclear program and the Israeli-Palestinian peace process.

He flies next to Paris where he is scheduled to holds talks Wednesday with Palestinian leader Mahmoud Abbas.

Kerry has spent months trying to get Israel and the Palestinians to agree on a framework to guide negotiations for resolving their long-running conflict.

The two sides resumed talks in July after a three-year break, but have made little visible progress.

During initial meetings, Israel agreed to a prisoner release, while the Palestinians dropped their demand for Israel to stop settlement construction before peace talks are held.