US Secretary of State John Kerry stressed Washington's support for Tunisia's young democracy during "strategic dialogue" Friday aimed at strengthening the partnership between the allies, including on the economic front.
"The eyes of the world are on Tunisia and America wants Tunisia to succeed," Kerry said at a joint press conference with his Tunisian counterpart Taieb Baccouche.
"The US remains deeply invested in strengthening Tunisia's economy," he added. The United States had given the North African country more than $700 million since its 2011 revolution.
Baccouche said the dialogue, after initial talks last year, involved military, security and economic cooperation.
A US State Department official said earlier that Kerry's visit was expected to examine a request from Tunis for an additional $500 million in loan guarantees.
Baccouche told reporters that a letter of intent had been signed to this effect, adding that Tunis was seeking a "five-year aid programme".
Unlike other regional countries plunged into chaos by the Arab Spring, Tunisia has managed its political transition, and Washington sees this as a response to those who claim that Islam and democracy are incompatible.
During his short visit, Kerry also met members of the National Dialogue Quartet who won the 2015 Nobel Peace Prize for their role in promoting a democratic transition after the revolution.
The Quartet comprises the Tunisian General Labour Union; the Tunisian Confederation of Industry, Trade and Handicrafts; the Tunisian Human Rights League; and the Tunisian Order of Lawyers.
It was formed in 2013 as the process of democratisation was facing huge challenges amid social unrest, threatening to drag Tunisia into civil war.
Before flying to Vienna for an international conference on Syria, Kerry also met President Beji Caid Essebsi, Tunisia's first democratically elected head of state who visited Washington in May seeking more military aid to counter a jihadist threat.
During the May visit, the United States designated Tunisia a major non-NATO ally.
Since the 2011 revolution that toppled veteran strongman Zine El Abidine Ben Ali, Tunisia has seen a rise in jihadist violence that has targeted security forces as well as the key tourism industry.
Jihadist attacks in Tunis and the seaside resort of Sousse in March and June killed 60 people, all but one of them foreign holidaymakers, dealing a heavy blow to the industry which accounts for almost 10 percent of GDP.
Earlier this year, Tunisia joined the US-led coalition fighting the Islamic State jihadist group that claimed the two attacks.
Tunisia, which has thousands of citizens in the ranks of organisations such as IS, is particularly concerned about the chaos in neighbouring Libya.
This summer, it began building a wall along the border with Libya that is expected to run some 200 kilometres (125 miles).
"Libya is a concern for Tunisia. The support of the United States would be welcome to help us secure the borders," Baccouche said.
With negotiations under the auspices of the United Nations yet to bear fruit, Kerry said he spoke on Thursday with the new UN envoy to Libya, Martin Kobler of Germany.
"ISIL obviously has tried to spread his tentacles into Libya," Kerry said, using an alternate acronym for IS.
Kerry said that in talks with Western officials he had raised the prospect of an international conference on Libya, "possibly some time in the next months".