U.S. Secretary of State John Kerry is pressing for a United Nations vote creating an arms embargo on South Sudan in an effort to end the civil war there, a U.S. official said Thursday.

An embargo and sanctions against South Sudan fighters are regularly discussed at the United Nations, and in Washington and Europe.

A U.S.-led coalition air strike killed a chemical weapons specialist with the Islamic State group in Iraq who once worked for Saddam Hussein, U.S. military officers said Friday.

The air raid carried out last Saturday near Mosul took out Abu Malik, whose training "provided the terrorist group with expertise to pursue a chemical weapons capability," the military said in a statement.

The United States gave a clear signal Wednesday that Russia will face further sanctions for what the White House says is Moscow's role in fueling violence in eastern Ukraine.

Following a telephone call between U.S. Vice President Joe Biden and Ukrainian President Petro Poroshenko, the White House condemned "Russian-backed separatists" and the "heavy toll that the Russian-backed offensive in the east was having on Ukraine's civilian population."

The United States welcomed Tuesday former Cuban leader Fidel Castro's belated response to the thaw in ties between the Cold War foes as a sign that change is under way in Havana.

"We take his reference of 'international norms and principles' as a positive sign," State Department spokeswoman Jen Psaki told reporters, after Castro's letter was released.

U.S. officials are holding discussions with representatives of the Shiite militia in Yemen who have forced the resignation of the country's president, a Pentagon spokesman said Tuesday.

But the discussions with the Huthi militiamen do not amount to an agreement to share intelligence on al-Qaida in Yemen, Rear Admiral John Kirby told reporters.

Labor Minister Sejaan Qazzi has called on the international coalition fighting the Islamic State terrorist group to defend Lebanon if it was invaded by terrorists.

Qazzi told An Nahar daily published on Tuesday that the Lebanese authorities should officially ask the coalition to make a pledge on protecting Lebanon against terrorist organizations.

Spain said Friday it was starting negotiations with Washington to host a permanent U.S. Marines intervention force for deployment on missions to Africa.

The Spanish government said it was ready to permanently extend an agreement under which the force has been based at Moron de la Frontera, near Seville in southern Spain.

World leaders paid tribute to Saudi Arabia's King Abdullah on Friday, praising the late monarch as   a key mediator between Muslims and the West.

U.S. President Barack Obama said he and Abdullah, whose country has for decades been a strategic ally of Washington, had enjoyed a "genuine and warm friendship". 

Top European diplomats on Thursday waded into the political fray in Washington over Iran, urging U.S. lawmakers to hold off on new sanctions and pleading for time to allow nuclear talks to succeed.

"Maintaining pressure on Iran through our existing sanctions is essential,"  four European foreign policy chiefs warned in a joint op-ed in the Washington Post.

Defiant Shiite militiamen seized control of Yemen's presidential palace and attacked President Abdrabuh Mansur Hadi's residence Tuesday in an apparent bid to overthrow the embattled government, drawing condemnation from the U.N. Security Council.

The council backed Hadi as "the legitimate authority" and called on all parties and political actors in Yemen to stand with the government "to keep the country on track to stability and security."