Discontent with American policy toward Iran is behind the last-minute pullout by Saudi King Salman from a summit with U.S. President Barack Obama this week, analysts said.

Obama invited Salman along with five other Gulf rulers to the White House on Wednesday followed by a retreat the following day at Camp David.

President Vladimir Putin is expected Tuesday to host U.S. Secretary of State John Kerry for crucial talks in Sochi amid tensions over Ukraine, during the top U.S. diplomat's first visit to Russia since the start of the crisis.

Ties between Moscow and Washington collapsed after Russia seized Crimea and buttressed separatists in eastern Ukraine but after a year of raging tensions signs are emerging that both Russia and the West may be ready to seek detente.

The United States acknowledged before the U.N. Monday that it has not done enough to uphold civil rights laws, following a string of recent killings of unarmed black men by police.

Speaking before the United Nations Human Rights Council, a U.S. representative stressed the advances his country had made in establishing a range of civil rights laws since segregation ended more than half a century ago.

Michelle Obama says she had to fight misperceptions due to her African-American race during the 2008 White House campaign that saw her husband become the first black president of the United States.

The first lady, who grew up in humble circumstances in Chicago and became a successful corporate lawyer, has rarely discussed race during her husband's two terms in office. 

Southeastern U.S. storm Ana weakened to a tropical depression Sunday after making landfall and slowing down over the coast, though forecasters warned of storm surges, rip currents and heavy rain.

Ana, which formed before the official June 1 start of the hurricane season, hit around the border of North and South Carolina early Sunday after barreling toward the coast overnight as a tropical storm.

Newly crowned Saudi King Salman has refused an invitation to attend a landmark summit hosted by President Barack Obama, amid angst over U.S.-Iran nuclear negotiations. 

Obama had invited six Gulf kings, emirs and sultans to the presidential retreat at Camp David, seeking to shore up wavering trust while Washington negotiates with regional power Tehran.

Ukraine's pro-Russian rebel leader Alexander Zakharchenko said Saturday that insurgents had released two US aid workers detained for alleged spying. 

"We have freed two Americans that we arrested earlier. One of the two is a CIA agent, the other was enlisted," Zakharchenko told journalists, without giving any more details. 

China's defence ministry said on Saturday that a U.S. report on its military which accused Beijing of ramping up land reclamation in the disputed South China Sea distorted facts, the official Xinhua news agency reported.

"The U.S. defence department’s report on China’s military and security development situation distorts facts and continues to play up the 'China military threat' cliché," Chinese defence ministry spokesman Geng Yansheng was quoted as saying.

From across the pond, President Barack Obama has warmly welcomed David Cameron's election victory, but with Britain's role in Europe and the world in doubt so too is its "special relationship" with the United States. 

White House congratulations are rarely more effusive.

A former Department of Energy employee has been indicted after attempting to hack agency computers to steal and then sell nuclear secrets to Iran, China and Venezuela, U.S. officials said Friday.

Charles Harvey Eccleston, 62, who also worked at the Nuclear Regulatory Commission, was snared in an FBI sting operation that was launched after he entered a foreign embassy and offered to hand over classified information, according to the affidavit.