With conflicts raging across the Middle East, the U.S. is seeking to reassure its Gulf allies that it has a regional strategy which will be bolstered, not shredded, by any Iran nuclear deal.

The U.S. administration appears increasingly caught in a game of whack-a-mole as it confronts a series of complex challenges, with Saudi-led airstrikes in Yemen just the latest complication in a regional tinderbox pitting Sunnis against Shiites, and even Sunni against Sunni.

Barack Obama is weak and Ronald Reagan exuded power, Republicans say. But while conservative White House hopefuls revere the 1980s president as a foreign-policy icon, oversimplifying Reaganism may mask nuances of his diplomacy.

Appreciation for the ex-president, who died in 2004, is nothing new. Buttons and posters bearing his countenance are common at conservative gatherings.

U.S. President Barack Obama said Friday he was not surprised that Russia lifted its ban on supplying missile systems to Iran, despite the move coming at the height of intense international talks on Tehran's nuclear program.

President Vladimir Putin, whose own government is under strict economic sanctions for Russia's involvement in unrest in Crimea and Ukraine, earlier this week removed the ban on supplying Iran with sophisticated S-300 air defense missile systems.

Two suspected al-Qaida militants were killed overnight in Yemen in a drone strike believed to have been carried out by the United States, a tribal source said on Friday.

The late night strike targeted a vehicle in Habban, southeast of Ataq, the  main town in southern Shabwa province.

The EU said Friday it will host fresh talks next week between prime ministers Aleksandar Vucic of Serbia and Isa Mustafa of Kosovo as part of efforts to normalize their ties.

EU foreign affairs chief Federica Mogherini will meet the two leaders in Brussels on Tuesday to promote the dialogue between the two neighbors which are at odds over Pristina's 2008 unilateral declaration of independence from Belgrade.

Deadlock over the controversial relocation of a U.S. military base in southern Japan deepened Friday when Prime Minister Shinzo Abe met the anti-base governor of Okinawa.

The two men remained as far apart as ever after a 30-minute meeting that analysts said was largely Abe going through the motions of consultation ahead of a key trip to the United States.

Hundreds of U.S. paratroopers have arrived in Ukraine to train its forces fighting pro-Russian rebels, the U.S. army said Friday, a move Moscow warned could "destabilize" the war-torn ex-Soviet country.

"Soldiers of the 173rd Airborne Brigade have been arriving over the last week," Donald Wrenn, a U.S. army spokesman, told AFP.

U.S. presidential contender Hillary Clinton will visit the key primary election state of New Hampshire early next week, after her first presidential election trip this week.

The former first lady and secretary of state -- now the clear frontrunner for the Democratic Party presidential ticket -- will meet with students, teachers and small business employees, he campaign team said Thursday.

Iraq's largest refinery in Baiji is not "at risk" despite an offensive by the Islamic State group that has breached parts of the facility, the U.S. military's top general said Thursday.

The IS militants have "penetrated the outer perimeter" of the vast oil refinery and the U.S.-coalition was concentrating bombing raids and surveillance flights over the area, General Martin Dempsey told reporters.

U.S., Japanese and South Korean diplomats Thursday renewed concerns about moves by China to stake its claim to disputed seas and urged Beijing to preserve freedom of navigation in the key waterways.

Deputy U.S. Secretary Tony Blinken repeated America's position that all competing claims in the South and East China Seas should be dealt with according to the rule of law.