A French aircraft carrier launched operations against the Islamic State jihadist group Monday as the new Pentagon chief summoned top generals and diplomats to Kuwait to review the war effort.

US Defence Secretary Ashton Carter vowed the jihadists would suffer a "lasting defeat" as he convened the meeting of more than two dozen senior military officers, ambassadors and intelligence officials at the sprawling US Army base of Camp Arifjan in Kuwait.

Afterwards, the new Pentagon chief indicated he supported the current strategy and did not call for a major overhaul.

"I think we have the ingredients of the strategy," Carter told reporters, adding that it was "a combined political and military effort".

A defence official confirmed Carter did not favour a radical overhaul of the war strategy, even though some US allies and Washington lawmakers have demanded a more aggressive stance in Syria.

"What today reaffirmed for the secretary is that the strategy is sound. The strategy is working," said the official, speaking on condition of anonymity.

However, the US-led coalition needs to counter the IS's use of social media more effectively, the official said.

Carter said the jihadists' exploitation of "social media will be pressing us to be more creative in combating it".

Although the fight against the extremists would require patience, Carter said "the discussion indicated clearly to me that this group is hardly invincible".

Washington forged a coalition of Western and Arab nations to confront IS after the Sunni extremist group seized control of large parts of Syria and Iraq and declared an Islamic "caliphate" last year.

- French carrier sorties -

The coalition has since carried out more than 2,500 air strikes against the jihadists, and France boosted its participation on Monday with the carrier Charles de Gaulle launching raids from the Gulf.

"This threat, jihadist terrorism, wants to reach our citizens, our interests, our values. France's response will be total firmness," Defence Minister Jean-Yves Le Drian said on board, seven weeks after extremist attacks killed 17 people in Paris.

Four Rafale and four Super Etendard jets took off from the carrier about 200 kilometres (120 miles) north of Bahrain, and returned after a five- to six-hour mission.

Rear Admiral Eric Chaperon, commander of the carrier group, said the aircraft carried out no strikes but familiarised themselves with the mission.

The carrier, with 12 Rafale and nine Super Etendard fighters, will spend eight weeks in the Gulf working alongside the USS Carl Vinson, significantly increasing France's regional air capabilities.

France, along with Australia, is a main contributor to the 32-member coalition effort aside from the United States, which is carrying out the bulk of strikes.

France and other Western nations are conducting operations over Iraq and several Arab nations are taking part in strikes over Syria.

Coalition aircraft launched 18 strikes against IS targets in Syria and seven in Iraq in the 24 hours to 0600 GMT on Monday, the Pentagon said.

- 'First objective attained' -

The air campaign aims to support fighters on the ground in Iraq and Syria, including rebels and Kurdish forces, battling IS and to hit infrastructure such as oil facilities seized by the jihadists.

"Air support... for our Iraqi and Kurdish allies has helped curb the territorial expansion of (IS) and stabilise the front lines. This was our first objective and it has been attained," Le Drian said.

While excluding the deployment of ground combat troops, coalition states have also sent training units to work with Iraqi forces.

US Lieutenant General James Terry, who oversees the anti-IS campaign, said some 800 Iraqi forces backed by US warplanes were fighting to retake Al-Baghdadi from IS.

The western Iraqi town is near the Iraqi army's Al-Asad base, where 300 US troops are stationed to train local forces.

IS influence has spread as it cements its hold on territory in Syria and Iraq, with jihadist groups in several countries pledging allegiance.

The Libyan branch claimed responsibility for suicide bombings last week that officials said killed 40, as well as the beheadings of 21 Coptic Christians, mostly Egyptian.

The coalition campaign has dealt significant damage to the jihadists, with a monitoring group saying Monday that 1,465 IS members had been killed in the first five months of air strikes in Syria.

Another 73 fighters from Al-Qaeda's Syrian affiliate Al-Nusra Front had been killed, as had 62 civilians, the Britain-based Syrian Observatory for Human Rights said.

US military officials have said they want Iraqi forces to launch an offensive to retake the strategic northern city of Mosul from IS in April or May.

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