The United States will intensify its efforts to destroy the Islamic State extremist group in Syria and Iraq, Secretary of Defense Ashton Carter pledged Friday.

A US-led coalition began bombing the group in both countries last year, after the jihadists overran large areas in a brutal campaign of beheadings and forced religious conversions.

The White House is, however, under growing pressure to do more, with President Barack Obama's administration criticized by opponents for what they say is a lack of discernable progress in eliminating the extremists.

"We are taking a number of steps... and we intend to take more to strengthen the execution of our strategy and hasten the defeat of ISIL," said Carter, speaking at a news conference in Washington alongside Michael Fallon, his British counterpart and ally in the bid to defeat the IS group.

"I expect in a week and two weeks and six weeks and so forth for us to be doing more and building more capability, and having more and more impact every week.

"That's the whole idea. That's what President Obama has asked to us to do, that's what we have been able to do and we will continue to do."

Obama will travel to the Pentagon Monday to take stock of the ongoing military efforts in Iraq and Syria.

The president will hunker down with his National Security Council and then make a statement, said his spokesman Josh Earnest. However, it is not expected to herald a major change in strategy.

Efforts to crush IS will extend to Libya: French PM
Paris (AFP) Dec 11, 2015 - International efforts to crush the Islamic State group will increasingly have to extend to Libya where the jihadists are getting a hold, French Prime Minister Manuel Valls said Friday.

"We are at war, we have an enemy, Daesh, that we must fight and crush in Syria, in Iraq and soon in Libya too," Valls said, using an Arabic acronym for the group.

Speaking four weeks since IS gunmen and suicide bombers attacked Paris, Valls told France Inter radio the threat of further outrages remained "because we have hundreds, even thousands of young people who have succumbed to radicalisation".

French planes carried out surveillance flights over Libya last week.

Libya has slipped into chaos since the fall of Moamer Kadhafi in 2011 which IS has exploited. The UN believes 2,000 to 3,000 fighters are operating there, including 1,500 in the coastal city of Sirte.

International talks will take place in Rome on Sunday aimed at helping the country form a unified government.

France intensified its air strikes on IS's stronghold in Syria after the group claimed responsibility for attacking Paris.

Dutch to decide 'by January' on Syria air strikes: PM
The Hague (AFP) Dec 11, 2015 - The Netherlands will not decide until next year whether to join US-led air strikes in Syria, Prime Minister Mark Rutte said Friday after America urged the Dutch to step up their effort.

"We are taking our time (with the decision). Certainly not before Christmas and hopefully in January," Rutte told a press conference after the weekly cabinet meeting.

Last week Dutch Foreign Minister Bert Koenders told lawmakers the country had received letters from both France and the United States requesting The Hague to join in the air strikes in Syria.

Efforts against the Islamic State group, which holds a swathe of territory in Iraq and Syria, have intensified in the wake of the November 13 attacks in Paris in which 130 people died.

Koenders also spoke last week to US Secretary of State John Kerry, who has been leading efforts to bolster the US-led coalition fighting the jihadist group.

"There is a case building whether we should bomb supply lines in Syria," Rutte told reporters Friday.

"But at the same time you also have to talk about the de-escalation of the conflict and all of this has to be brought into balance," Rutte said.

"These are serious questions and we are looking at them carefully."

The Netherlands is already participating in the coalition by carrying out air strikes in Iraq, with four F-16 aircraft specialising in close air support of ground operations by Iraqi forces.

Several centre-right and right-wing lawmakers have called for strikes in Syria and Rutte's own ruling Liberal VVD party has said it would support such a cabinet decision.

The Netherlands' top military chief, General Tom Middendorp has also backed a stepped up bombing campaign.

But the government's junior coalition partner, the Labour party (PvdA), is against.

The four Dutch F-16 jet fighters have been pounding IS jihadists in Iraq since October 2014, but The Hague at the time said it would not carry out air strikes over Syria without a UN mandate.

Observers have said Britain's decision to join France and the US in air strikes against IS over Syria last week put further pressure on the Dutch to join the campaign.