Human rights groups had urged Mr Kerry to make a major statement on the state of human rights in both Turkmenistan and Uzbekistan, countries they regard as among the most oppressive in the world.

Instead, Mr Kerry, in public at least, spoke about joint security concerns and about the need to keep democracy at the forefront of the region’s governance.

“In Central Asia and elsewhere people have a deep hunger for governments that are accountable and effective,” he was quoted as saying.

“We should have no doubt that progress in democratic governance does lead to gains in every other field.”

Perhaps Mr Kerry’s most important objective on his trip of the region was to reassure the leaders’ of the various countries that the United States was still interested in Central Asia despite quitting an air base outside Bishkek and appearing to cede influence to Russia and China.

Mr Kerry met Uzbek President Islam Karimov in Samarkand and later Turkmen president Kurbanguly Berdymukhamedov in Ashgabat. Mr Kerry was the first US Secretary of State to visit Ashgabat since James Baker in 1992, shortly after the collapse of the Soviet Union.

Media quoted Kerry at the end of his tour of Central Asia, summing up his most important aims.

“What we want to see is not a struggle between China and Russia and the United States in a zero-sum game,” he said. “What we want to see is a Central Asia that claims its place as an engine of growth at the heart of a modern and dynamic Asia.”