BISHKEK — Security issues dominated talks between the European Union's top envoy and Central Asian diplomats Tuesday as the looming withdrawal of the international military coalition from Afghanistan raises the specter of regional instability. EU foreign policy chief Catherine Ashton said after a meeting with regional foreign ministers in Kyrgyzstan, host of a vital US air base, that Europe's growing interest in Central Asia was based on shared security challenges. “In this region, we face increasing and new challenges. We talked about developments in Afghanistan and the importance of the future of that country,” Ashton said. Ashton said she wanted to see deeper cooperation on energy and trade with Europe, but avoided addressing what advocacy groups say are worsening political freedoms in Central Asia. “We want to support you on the efforts that you're making on political and economic reform, so that we can unlock the potential in the relationship between us,” Ashton said. Ashton will also visit Uzbekistan, Kazakhstan and Tajikistan over the coming week. All these countries have expressed anxiety about the potential for spillover from unrest in Afghanistan after the US drawdown in 2014. Another threat to the stability of the region discussed Tuesday was the rivalry over water resources between Uzbekistan, Kyrgyzstan and Tajikistan, which has tested relations among the mainly Muslim former Soviet states to breaking point. Kyrgyzstan and Tajikistan's hopes of developing hydropower are resisted by Uzbekistan, a populous nation of almost 30 million that sees the creation of dams as a threat to its substantial agricultural industry. “The promotion of long-term solutions to water and (renewable energy) is of great importance to you and this region,” Ashton said. Advocacy groups regularly express disappointment at what they say is an insufficiently tough approach on human rights in Central Asia from the EU. “Promises are good, but what is needed is frank talk to her hosts about the need to free detained human rights defenders and to stop harassing activists if they want closer ties,” Lotte Leicht, EU advocacy director at Human Rights Watch, said in a statement ahead of Ashton's tour. Ashton said Tuesday's talks also encompassed freedom of the Internet, the role of women, and the development of parliamentary models in a region dominated by Soviet-style hardliners. The region includes some of the most democratically underdeveloped in the world. Uzbekistan and Turkmenistan, which was the only nation not represented Tuesday by a foreign minister, in particular have consistently rebuffed calls for reform. Uzbekistan lies on a vital supply route for international troops in Afghanistan and will also play a major role in the withdrawal of troops and equipment. Turkmenistan has been mired in self-imposed diplomatic isolation for the duration of its independence, but is being actively courted by the West for access to its copious natural gas resources. Tajikistan — a poor and mountainous nation with a long and porous border with Afghanistan that is a major conduit for the heroin trade — provoked indignation this week after barring access to social networking website Facebook for the second time this year. — AP