He also said that negotiations to conclude a wide-ranging trade agreement with the US continued, despite political controversy over it.

"President [of the commission, Jean-Claude] Juncker launched a challenge about this idea of having a single headquarters in Europe for military operations in the European Union, not to substitute any type of military force, but to have here a joint organisation and coordination of all European military forces," said Moedas, who has responsibility for research, science and innovation, at a hearing of the committee on European affairs of Portugal's parliament.

Moedas explained that the aim was not to create a "common army", but to ensure a "coordination of the armies of each country". He also ruled out the possibility of countries interfering in each others' military affairs.

"The idea is not interference, but the sharing of information," he told deputies, adding that it was "essential" to improve European defence. According to Moedas, information has not been shared correctly and that the lack of cooperation in the field in the EU is currently costing more than €25 billion a year.

The idea prompted some reservations among members of Portugal's parliament, with Miguel Morgado of the opposition Social Democratic Party, of whose last government Moedas was a member, recalling that some EU states, "because of their own position of neutrality", could never merge their military operations. Francisca Parreira, a member of the governing Socialist Party, described as "pernicious" the idea of a headquarters that could interfere in military forces whose key role is defending national frontiers.

At the same hearing, Moedas said that talks between US and EU officials on the controversial Transatlantic Trade and Investment Partnership (TTIP) continue, despite French officials having said the opposite.

"We continue to negotiate as we have always negotiated," he said. "There was a unanimous mandate" from EU governments to do so, he pointed out.

On the French government's public stance on the issue, the commissioner said that "there are comments by politicians who know that they have no practical effect" and said that they were an example of "political comments in the bad sense".