The West's defence of Charlie Hebdo's right to offend is testing the patience of Muslims even in moderate Indonesia and Malaysia, who fear it could fuel radical sentiment kindled by the Islamic State group.

Publicly, the issue has stirred barely a ripple in the Southeast Asian neighbours, underscoring their cultural and philosophical gap with the rest of the Muslim world, where it has triggered outrage.

A group of pro-Syrian regime hackers briefly took over the Twitter account of France's Le Monde newspaper early Wednesday, tweeting several messages including one reading "Je ne suis pas Charlie".

The tweet was a negative reference to the "Je Suis Charlie" (I am Charlie) hashtag that became a popular way of showing solidarity in the wake of this month's Islamist attack on Paris magazine Charlie Hebdo that left 12 people dead.

Washington stands side-by-side with victims of terror around the world, President Barack Obama vowed Tuesday, asking lawmakers to give him updated war powers to defeat Islamic militants in Iraq and Syria.

"We stand united with people around the world who've been targeted by terrorists --  from a school in Pakistan to the streets of Paris," Obama said in the country's annual State of the Union address.

U.S. lawmakers Tuesday roundly condemned the recent attacks in France that killed 17 people, and called on governments worldwide to support free speech and counter violent extremism.

Hours before President Barack Obama's State of the Union address before both chambers of Congress, the Senate and House of Representatives each unanimously passed a resolution condemning the bloody attacks in Paris.

Press freedom is increasingly "under siege," U.S. Secretary of State John Kerry warned Tuesday as he paid tribute to the slain journalists of the French satirical magazine Charlie Hebdo.

"The truth is that freedom of the press, whether symbolized by a pencil, a pen, a camera, or a microphone is under siege, purposefully," Kerry told a conference called to examine ways to improve security for journalists.

The leader of France's far-right National Front (FN) said Tuesday she hopes the radical left-wing Syriza party will win Greece's general election.

Marine Le Pen's comment to Le Monde newspaper drew an angry reaction from Syriza, with one senior party member calling her support "false and disgusting".

The city of Paris said Tuesday it plans to sue U.S. chain Fox News for reports that there were "no-go zones" in the French capital that police and non-Muslims avoid.

The reports in the wake of the Islamist attacks in Paris two weeks ago have been widely derided and prompted Fox to issue an on-air apology for suggesting parts of Paris and the English city of Birmingham were run under Islamic Shariah law.

Belgian authorities are hunting for two men on the run after a jihadist cell was broken up in Belgium last week, with the search focusing on Spain and France, a source close to the investigation in Spain said Tuesday.

Belgium issued arrest warrants on Sunday for the two men, born in 1993 and 1996, to police in Spain and France, the source told AFP, confirming reports in the Spanish and Belgian media.

The foreign ministers of Ukraine, Russia, Germany and France are set to meet Wednesday in Berlin in a bid to de-escalate the Ukraine conflict, Germany said.

"The chief aim now is to prevent a further deterioration of the military conflict and a renewed political escalation between Kiev and Moscow. This is worth every effort," German Foreign Minister Frank-Walter Steinmeier said in a statement.

A Bulgarian court ruled Tuesday that a Frenchman who admits knowing the Charlie Hebdo attackers but denies being an Islamic extremist could be extradited to France following an arrest warrant issued by Paris.

Muslim convert Fritz-Joly Joachin, 29, arrested on January 1 as he tried to cross from Bulgaria into Turkey, told the court in Haskovo in southern Bulgaria: "I am innocent. I want to return to France."