The delivery of Russian S-300 air defense missiles to Iran will not affect America's ability to strike at Tehran's nuclear facilities if necessary, the top U.S. military officer said Thursday.

"We've known about the potential for that system to be sold to Iran for several years and have accounted for it in all of our plans," General Martin Dempsey, chairman of the U.S. Joint Chiefs of Staff, told a news conference.

The U.S. state of Texas killed its sixth death row inmate of the year Wednesday, prison officials said, after replenishing a lethal injection drug that some manufacturers have refused to sell for executions.    

Manuel Garza, 35, was declared dead by lethal injection at 6:40 pm (23:40 GMT) in the execution chamber in Huntsville, said Texas prisons spokesman Jason Clark.

President Nicolas Maduro said Tuesday he had launched a probe into reports of Panama-based Venezuelans who may have illegally obtained wealth.

Maduro, whose socialist government is in economic crisis amid historically low oil prices, said on his television show "In Touch with Maduro" that he suspects many may have settled in Panama with laundered money or breaking his rules aimed at stemming currency flight.

Australia's defense minister has been left red-faced after apparently being unable to name the head of Islamic State on the day he committed more troops to help defeat the jihadist group.

Kevin Andrews was repeatedly asked during a television interview with the Australian Broadcasting Corporation late Tuesday to identify the IS chief -- widely seen as Abu Bakr al-Baghdadi.

President Barack Obama's move on Tuesday to drop Cuba from a list of state sponsors of terrorism was "fair," the foreign ministry in Havana said.

"The government of Cuba acknowledges the fair decision of the president of the United States to take Cuba off a list on which it should never have been included," said a statement signed by Cuba's top official for relations with Washington.

North Korea celebrated the birth anniversary Wednesday of founder Kim Il-Sung, with current leader Kim Jong-Un paying respects at his grandfather's mausoleum, as rights groups highlighted his "horrific" human rights legacy.

At the stroke of midnight, Kim Jong-Un, accompanied by top military leaders, visited the Kumsusan Palace of the Sun in Pyongyang -- the mausoleum holding the embalmed body of his grandfather, the North's official KCNA news agency said.

The U.S. military is well equipped to defend the country against cyberattacks but is not yet ready to wage digital warfare, a senior defense official told lawmakers on Tuesday.

The military's cyber command, created in 2009, lacks the means to lead an offensive campaign in a fast-moving digital conflict, said Eric Rosenbach, the Pentagon's principal adviser on cyber security.

Hundreds of American citizens and their families have fled Yemen on foreign ships, joining an exodus of terrified people fleeing intense airstrikes against Shiite rebels, a U.S. official said Tuesday.

They have been brought to safety on board Indian, Korean and Russian ships sailing from Yemen across a narrow channel of the Red Sea, only 30 kilometers (20 miles) wide, to Djibouti in the Horn of Africa.

The U.S. State Department offered assurances Tuesday that it had strengthened the rules governing private security firms in the wake of a 2007 shooting in Iraq in which 14 people died.

A former Blackwater guard was sentenced to life in prison and three others received 30-year sentences Monday for their roles in the mass shooting in which 17 people were also injured.

Hundreds of New Yorkers took to the streets on Tuesday to protest against fresh police killings of unarmed black men, disrupting traffic on the Brooklyn Bridge after marching through Manhattan.

The crowd of black, white and Latino youths held placards saying "stop police murder," "black lives matter" and calling for justice for African American men shot dead by U.S. officers in recent months.