European Commission President Ursula von der Leyen has said the EU should seek to beef up its military capabilities to confront security threats and global crises.
She told the European Parliament she believed EU military forces would be "part of the solution".
After the Afghan pull-out the EU needed the "political will" to intervene militarily without US-led Nato.
France will host an EU defence summit next year, she added.
"It is time for Europe to step up to the next level," Mrs von der Leyen said in her annual State of the Union address.
The EU has historically relied on the Nato alliance for military action.
The rapid collapse of Afghanistan's government at the end of the US-led mission in the country last month has raised questions about the EU's ability to drive its own defence policy.
Earlier this month German Defence Minister Annegret Kramp-Karrenbauer called for intense talks on making the EU "a strategic player to be reckoned with".
Her comments echo those of other EU leaders, including French President Emmanuel Macron, who has backed the idea of a European army.
The UK's departure from the EU has also brought security into sharp focus, partly because it was opposed to building a new European intervention force.
A 'lack of political will'
Proposals for an EU rapid-response force first emerged in the 1990s.
In 1999, member states pledged to develop a military force of up to 60,000 soldiers. In 2007, so-called battlegroups of 1,500 troops drawn from each member state were created.
The battlegroups were declared ready for operations but have never been used because of disputes over funding and a reluctance to deploy.
"You can have the most advanced forces in the world - but if you are never prepared to use them, of what use are they?" the Commission president told the Strasbourg parliament.
"What has held us back until now is not just a shortfall of capacity - it is the lack of political will."
Most EU nations are also members of Nato and some, particularly states neighbouring Russia, do not want to undermine ties with the US.
Nato Secretary-General Jens Stoltenberg said this month he supported EU plans to build a common defence policy, but warned against the creation of a new military force.
Mrs von der Leyen explained that the EU had to provide greater stability in its own neighbourhood and elsewhere, taking part in missions that did not include Nato and the UN. It also had to tackle cyber-threats by becoming a leader in cyber-security.
A joint declaration would be made with Nato by the end of the year, she added.
The Commission president also said:
The EU would "stand by the Afghan people" and increase humanitarian aid for Afghanistan by €100m (£85m; $118m)
The forthcoming COP26 climate summit in Glasgow would be "a moment of truth for the global community". She called on the US and China - the world's biggest polluters - to step up their commitments to curbing climate change
The Covid-19 pandemic was "a marathon, not a sprint". She announced more funding and vaccine donations to low-income countries to ensure "this doesn't turn into a pandemic of the unvaccinated"
EU member states had a responsibility to defend European values, including the right to an independent judiciary
The Belarus government had "instrumentalised" migrants by sending them to the borders of EU nations. She accused Belarusian President Alexander Lukashenko of "a hybrid attack to destabilise Europe"
The European Commission would develop a new chipmaking "ecosystem", to keep the EU competitive and self-sufficient