North Korea Sunday described U.S. President Barack Obama as a "loser" over his criticism on its regime, accusing him of being obsessed with hostility towards Pyongyang.

The comment from the North's foreign ministry came after Obama spoke of the eventual collapse of the regime ruling what he called "the most isolated, the most sanctioned, the most cut-off nation on Earth". 

Libya's Ansar al-Sharia jihadist group on Saturday confirmed the death of its leader Mohamed al-Zehawi, after Islamist websites reported he had been mortally wounded in fighting in October.

"We mourn the death of the Emir of Ansar al-Sharia Sheikh Mohamed al-Zehawi," the group said in a statement, without giving details about the time or circumstances of his death.

A Canadian man will go before a New York court on Saturday accused of murder and conspiracy over the killing of five U.S. soldiers in Iraq, American prosecutors said.

Faruq Khalil Muhammad Isa, 36, allegedly helped to orchestrate a truck bombing carried out by a Tunisian jihadist on a U.S. base in Mosul, northern Iraq, on April 10, 2009 that killed the five American soldiers.

The United States and Iraq are preparing to retake Iraq's second-largest city Mosul from the Islamic State group by this summer,  The Wall Street Journal reported Thursday.

A group of Kurdish fighters and other Western-trained forces should be ready to launch the offensive by the spring or summer, the head of the U.S. military's Central Command General Lloyd Austin told the Journal.

The United States believes it has killed about 6,000 jihadists in its air strikes against the Islamic State group, defense officials said Thursday.

U.S. President Barack Obama will not meet Benjamin Netanyahu when the Israeli prime minister makes a controversial visit to the United States in early March, the White House said Thursday. 

National Security Council spokeswoman Bernadette Meehan said it was a "matter of long-standing practice and principle" that the president not meet candidates or incumbent leaders while they on the campaign trail.

The U.S. has urged Myanmar to investigate the deaths of two teachers who activists claim were raped and murdered by government troops, as crowds gathered in the country's far north Thursday to express rising anger over the killings.

The battered bodies of the two women, aged 20 and 21, were found Monday in a remote village in Shan state where they were teaching children on behalf of the Kachin Baptist Convention, according to KBC spokesman Lama Yaw.

A death-row inmate in Texas who confessed to murdering three elderly people with a screwdriver for just $100 was executed on Wednesday, U.S. prison authorities said.

Arnold Prieto, 41, was declared dead at 6:31 pm (00:31 GMT) at the state penitentiary in Huntsville, said Texas Department of Criminal Justice spokesman Jason Clark.

Diplomats from Iran and the U.S. are to meet again in Switzerland this week as the pace intensifies for a nuclear deal with Tehran, U.S. officials said Wednesday.

Top U.S. negotiator Wendy Sherman will travel to Zurich to meet with Iranian officials on Friday and Saturday, less than a week after leading face-to-face negotiations in Geneva, the State Department announced.

U.S. Secretary of State John Kerry accused pro-Russian separatists Wednesday of attempting "a blatant land grab" in fresh fighting in eastern Ukraine.

The U.S. was "particularly concerned" by a rebel initiative to "attempt to gain control of a very significant rail juncture" in eastern Ukraine in violation of a September ceasefire deal, he said, calling it "an effort to try to broaden the amount of territory that is being held."