By targeting the Islamic State group with air strikes in Libya, Egypt's President Abdel Fattah al-Sisi, having crushed Islamist opponents at home, has become a key ally of the West against jihadists, experts say.

His warplanes bombed IS camps and weapons stores in the Libyan city of Derna hours after the Sunni extremists released a gruesome video showing masked jihadists beheading 21 Egyptian Christians on a Libyan beach.

Japan on Tuesday announced $15.5 million to fight "terrorism" in the Middle East and Africa, as Tokyo tries to demonstrate its resolve despite the murder of two citizens by Islamist extremists.

The amount doubles the $7.5 million in assistance that Foreign Minister Fumio Kishida pledged during a visit to Brussels in January.

France on Monday signed its first export contract for Rafale fighter jets, with Egypt agreeing to buy 24 of the warplanes.

Eric Trappier, chief executive officer of France's Dassault Aviation, signed the multi-billion-euro contract at a presidential palace in Cairo in the presence of Egyptian leader Abdel Fattah al-Sisi and French Defense Minister Jean-Yves Le Drian.

The chaos in Libya since Moammar Gadhafi's downfall has proven fertile ground for the Islamic State group, prompting increasing calls for foreign intervention to uproot the jihadists.

In a video released Sunday, IS said it beheaded 21 Egyptian Christians on a Libyan beach, in a likely bid to strike fear and show the Sunni extremists' reach now stretches beyond its Iraqi and Syrian strongholds.

The U.N. Security Council on Monday condemned the apparent beheadings of 21 Egyptian Christians by Islamic State militants in Libya as "heinous and cowardly," and urged member states to "combat by all means" such threats to international peace.

U.N. Secretary General Ban Ki-moon also denounced the killings, which were shown on a video posted Sunday on the Internet.

Italy on Monday ruled out military intervention in Libya in the short term, despite mounting concern in Rome over the country's exposure to the fallout from the chaos engulfing its former colony.

The country's defense and foreign ministers have, in recent days, aired the possibility of Italy leading a U.N.-backed force on a mission to stabilize Libya and address the potential threat posed by Islamic militants establishing a base within easy reach of Europe.

Cairo carried out air strikes against Islamic State group targets in Libya on Monday after the jihadists posted a video showing the beheadings of 21 Egyptian Christians.

Egypt said a "tough intervention" was needed and with France called on the U.N. Security Council to "take new measures" against the jihadists in neighboring Libya.

Egypt's leader vowed to punish the "murderers" responsible for the beheading of 21 Egyptian Christians after the Islamic State group in Libya released a video on Sunday purportedly showing the mass killing.

A visibly angry President Abdel Fattah al-Sisi said Egypt "reserves the right to respond in a suitable way and time" in a televised speech, and declared seven days of mourning after the video was distributed by jihadists on social media.

Al-Jazeera journalist Mohamed Fahmy said Saturday he has urged Canada to push for his speedy deportation from Egypt after he spent more than 400 days in a tiny prison cell.

On Thursday, a court ordered that Fahmy and his colleague, Egyptian producer Baher Mohamed, be freed pending their retrial.

The U.S. said Friday that France's multibillion-dollar sale of Rafale fighter jets to Egypt was no cause for worry, despite Cairo's close defense-sales relationship with America.

"Egypt is a sovereign country," State Department spokeswoman Jen Psaki said. "We have our own security relationship, so I wouldn't say there's a concern from this end."