EU foreign affairs head Catherine Ashton begins a trip to China and Mongolia on Wednesday, aiming to take stock of hugely important ties with the new leadership in Beijing.
"China has just completed its leadership change and this is a moment to renew ties, take stock of events in the world and assess how we can best move forward and work together," Ashton said in a statement.
It said the agenda will focus on international issues including Iran, Syria, North Korea and Afghanistan, and that Ashton will meet Chinese Foreign Minister Wang Yi and Defence Minister Chang Wanquan, among others.
The EU and China are major trading partners but ties have been strained at times by disputes over market access.
On the political level, Beijing has consistently backed greater European integration but has resented EU criticism of its human rights record, which it sees as interference in its internal affairs.
Human Rights Watch said Wednesday however that Ashton should press the issue when she is in Beijing and especially the case of imprisoned writer Liu Xiaobo who won the Nobel laureate in 2010.
"Ashton cannot ignore the deteriorating human rights environment in China," the group said in a statement, arguing that EU efforts so far have had little impact.
China has just completed a transition to a new generation of Communist Party and government leaders, with President Xi Jinping and Prime Minister Premier Li Keqiang both anxious to keep the economy on track and assert the country's place on the international scene.
Ashton's visit to Mongolia is the first at this level, the statement said, adding she will meet Mongolian President Tsakhiagiin Elbegdorj and Prime Minister Noroviin Altankhuyag.
She is to sign a Partnership and Cooperation agreement with Mongolia, "paving the way for closer cooperation on economic, environmental and other issues," it added.