Romano Prodi, president of the European Commission, called on China to make more substantial progress on human rights, but said the European Union did not link rights to the possible lifting of an arms embargo.
"As you know there are still some differences among European governments and in our discussions I didn't put this as a precondition," he said on Wednesday.
"But I underlined twice how it is important for European public opinion, substantial progress in human rights." He declined to say what specifically that meant.
The embargo was imposed after the 1989 crackdown on democracy demonstrators in and around Beijing's Tiananmen Square. France argues the ban is anachronistic given improved relations between the EU and China.
China's ratification of the International Covenant on Civil and Political Rights was also not explicitly linked to the lifting of the arms embargo, but Prodi said he had pushed China's leadership to do so.
"I insisted on that and had a positive answer," he told reporters. He said there was "an engagement in this direction".
Prodi was speaking a day after talks with Chinese Premier Wen Jiabao, but ahead of a meeting with President Hu Jintao.
Ending the arms embargo could open up lucrative trade opportunities with the world's fastest growing major economy, which now has a large and widening trade surplus with the EU.
Some EU member states, however, are reluctant to rush into a move which could antagonise the United States, saying it would need to be justified by clear evidence that China's human rights practices had improved.
Diplomats have said Britain, under pressure from the United States, has stepped up opposition to lifting the embargo in recent days.
China suspended its human rights dialogue with the United States in March after Washington proposed a resolution condemning China's record at the annual session of the UN Human Rights Commission. Beijing accused Washington itself of being a rights offender.
China insists that fundamental human rights mean feeding, clothing and housing its 1.3 billion people and that individual rights should take a back seat.