EU foreign policy chief Catherine Ashton called on Prime Minister Recep Tayyip Erdogan to show Turkey's democratic credentials and opt for dialogue with anti-government protesters as Ankara seeks to win membership into the bloc.
Delivering her first public statement on the troubles in Turkey in a speech to the European Parliament, Ashton said Erdogan's response in talks with the protesters later Wednesday must be "engagement not antagonism," she stressed.
"This is an important moment for Turkey. A chance for it to renew its commitment to European values," she said. "I am convinced it can meet this challenge."
Ashton added that "Turkey as a candidate country needs to aspire to the highest possible democratic practices".
But Ashton said that the EU should not pull back despite concerns over Erdogan's handling of the protests.
"This is not the moment to disengage from Turkey but to engage more closely. And for Turkey to engage more closely with the EU too."
Turkey's efforts to join the EU formally started in 2005 but have stalled in recent years over its human rights record and the row over EU-member Cyprus, whose northern third is occupied by Turkey.
Ashton stressed that democratically elected governments must take account of those who do not feel represented. "And peaceful demonstrations are a legitimate way for such groups to express their views."
She also criticised the Turkish media's "initially sparse" coverage of the protests as well as attempts to condemn and restrict social media. "Freedom of the media is a concern in Turkey," she said.
And Ashton had harsh words for the use by police over the past two weeks of tear gas, water cannon, paper spray and plastic bullets against protestors who have been "overwhelmingly peaceful."
"Excessive use of force by members of the police against peaceful demonstrators must be swiftly and thoroughly investigated and those responsible held accountable", Ashton said.