US Secretary of State John Kerry tours the Registan cultural site in Samarkand on Sunday.

AFP/Samarkand

US Secretary of State John Kerry brought his Central Asia diplomatic caravan to the Silk Road citadel of Samarkand on Sunday.

President Islam Karimov, the 77-year-old autocrat who has ruled Uzbekistan for a quarter century since independence, hosted Kerry at his sprawling palace complex.

Kerry was keen to discuss closer US economic ties with Central Asia and cooperation in the battle against the Islamic State group, which recruits in the region.

But his willingness to court such a hardline figure will attract criticism from human rights groups.

The US envoy praised the beauty of Samarkand's monuments, comparing the ancient centre of Islamic learning favourably to the devastation wrought on famed Syrian sites by IS jihadists.

"We need to talk about the challenges that all of us face regarding security," Kerry added, noting that Central Asia borders on war-torn Afghanistan.

The two did not take questions. After the brief remarks, they met behind closed doors.

State Department spokesman Mark Toner said the two conversed on "respect for human rights and political freedoms" among other issues.

Kerry, who on Saturday had a difficult discussion on human rights with his counterpart in neighbouring Kyrgyzstan, has said he will not shy away from admonishing his hosts on his tour.

But he has also made it clear that Washington is ready to work more closely with Central Asian governments in the fight against extremists like the Islamic State group.

Later on Sunday, Samarkand was the backdrop for the first ministerial meeting between the US and all five Central Asian powers.

Kerry and the foreign ministers from Kyrgyzstan, Uzbekistan, Kazakhstan, Tajikistan and Turkmenistan met over lunch after making brief introductory statements, also signing a joint communique.

All agreed on the need for closer economic cooperation.