Germany can offer France Tornado reconnaissance jets, a naval frigate, aerial refuelling and satellite images to back the fight against the Islamic State jihadist group, the defence minister said Thursday.

"France was struck to the bone by the horrific attacks by the IS but we know that this inhumane rage can hit us or other societies at any time too," said Ursula von der Leyen, announcing the military support.

The offer will still have to be formally approved by Chancellor Angela Merkel's cabinet and supported by parliament, where Merkel's "grand coalition" however has an overwhelming majority.

The offer came a day after Merkel pledged in Paris to "very soon" decide how to help its closest EU ally battle the IS group in Syria, and after she met cabinet ministers in charge of security and the major parties' parliamentary groups.

The government had agreed on "difficult but correct and necessary steps", said von der Leyen at a press conference in the Reichstag building, flanked by Foreign Minister Frank-Walter Steinmeier.

She said Germany could send Tornado aircraft fitted with surveillance technology that can take high-resolution photos and infrared images, even at night and in bad weather, and transmit them in real time to ground stations.

A German frigate could help protect the French aircraft carrier Charles de Gaulle in the eastern Mediterranean, from which fighter jets carry out bombing runs, and the tanker aircraft could refuel them mid-air to extend their range, she said.

- 'More active role' -

Steinmeier said the political process must continue to find a solution to the Syrian conflict, but added that "we also won't get there without ... a military confrontation against the IS, al-Nusra and other terrorist groups in Syria".

Earlier Thursday the defence policy spokesman of Merkel's conservative CDU/CSU parliamentary group, Henning Otte, had pledged that "Germany will play a more active role than before".

Otte said Germany would go beyond its current arms shipments to and training of Iraqi Kurdish peshmerga forces combating IS.

"We are not only strengthening the training mission in northern Iraq, but will step up our commitment in the fight against IS terror, among other things with RECCE reconnaissance Tornados," he said.

Post-war Germany has been traditionally reluctant to send troops abroad, although it has joined UN-mandated missions in the Balkans and elsewhere, and the NATO coalition in Afghanistan.

Germany has not taken part in air strikes against the IS in Syria and Iraq, which have been mainly flown by US and French aircraft.

Otte said that "the IS can only be defeated militarily, therefore no idea must be ruled out as we engage in the fight against Islamist terrorism".

"Islamist terrorism is a threat to Germany and to world peace. Together with France and all other countries that oppose Islamist terror, we will provide everything necessary to the battle."

On Wednesday, von der Leyen said Germany would deploy 650 more troops to Mali to relieve the French-led mission there.