From Washington, this is VOA news. I'm Sarah Williams reporting.

Iraqi Prime Minister Haider al-Abadi has formally rejected a bid from Turkey to participate in the military push to retake the northern Iraqi city of Mosul from Islamic State extremists.

Abadi said Saturday the existing alliance will handle the ongoing battle without Turkey's help.

Abadi spoke in Baghdad after unscheduled talks with visiting U.S. Defense Secretary Ash Carter, who has sought to ease rising tensions between Turkey's Sunni leadership and Abadi's Shiite government.

Turkish President Recep Tayyip Erdoğan on Tuesday gave voice to the frayed bilateral ties, demanding a role in the Mosul battle and warning that Turkish troops already positioned in northern Iraq would not take orders from the Shiite government in Baghdad.

Republican presidential nominee Donald Trump offered new immigration reform proposals and said he would cut taxes for middle-class Americans by 35 percent during his first 100 days in office, should he win the presidency in next month's election.

Trump also commented on the dozen more women who have come forward to accuse him of sexual assault.

"On November 8th, Americans will be voting for this 100-day plan to restore prosperity to our economy, secure our communities, and honesty to our government. This is my pledge to you. And if we follow these steps, we will once more have a government of, by and for the people."

Trump gave his policy speech in Gettysburg, Pennsylvania, near a Civil War battlefield site.

This is VOA news.

The United Nations and officials from the Organization for the Prohibition of Chemical Weapons say the Syrian government is responsible for a third chemical attack that affected a region already torn by war.

The group's fourth report during a 13-month investigation sent to the U.N. Security Council late Friday shows there is "sufficient evidence" to confirm the government's role in the March 16, 2015 strike on Qmenas in Idlib governorate.

The report blames President Bashar al-Assad's government for using several barrel bombs containing chlorine gas dropped by military helicopters.

U.N. High Commissioner for Human Rights Zeid Ra'ad al-Hussein says the siege and bombardment of Syria's northern city of eastern Aleppo constitute crimes of historic proportions. He is calling on the 47-member U.N. Human Rights Council to refer the situation to the International Criminal Court. Lisa Schlein reports for VOA from Geneva.

High Commissioner Zeid says well over 300,000 Syrians have been killed and countless others wounded and traumatized in the course of more than five years of civil war.

Without mentioning Russia by name, the high commissioner blames the indiscriminate airstrikes across the eastern rebel-held part of Aleppo by government forces and their allies.

The chair of the International Commission of Inquiry on Syria, Paulo Sérgio Pinheiro, agrees.

"Perpetrators of war crimes and crimes against humanity will only cease to violate the laws of war when it is clear that they will be held to account."

Pinheiro says members of the investigative commission will continue to document war crimes in Aleppo.

Lisa Schlein, for VOA news, Geneva.

An Afghan Taliban delegation has traveled to Pakistan from Qatar for talks with officials to raise various issues, including "arrests" of some insurgent leaders, shutting down of some religious seminaries for Afghan refugees and "increasing problems" facing the displaced community in the neighboring country.

Somali pirates Saturday released 26 sailors who were captured during a ship hijacking nearly five years ago, bringing to an end one of the longest-running hostage taking cases in the country.

Sources close to the pirates told a VOA reporter in the region that hostages were released after their captors were paid a $2 million ransom, a claim repeated by one pirate in an interview with a local media outlet.

The crew consisted of members from Cambodia, China, Indonesia, the Philippines, Taiwan and Vietnam.

I'm Sarah Williams in Washington.

That's the latest world news from VOA.