From Washington, this is VOA news. I'm Steve Karesh reporting.

On Tuesday, U.S. President Barack Obama delivered his final address to the U.N. General Assembly, reviewing the progress he made during his presidency.

But he said he does believe the progress is threatened by the rise of religious fundamentalism, aggressive nationalism and crude populism.

"Each of us as leaders, each nation can choose to reject those who appeal to our worst impulses and embrace those who appeal to our best. For we have shown that we can choose a better history."

That message was echoed by Nigerian President Muhammadu Buhari as he touted his country's fight against Boko Haram.

"I take the opportunity to reaffirm Nigeria's commitment to human rights norms and international and humanitarian law in our efforts to counter terrorism and violent extremism."

Meanwhile, within earshot of the U.N. is the site where peaceful demonstrations are held during the General Assembly. At this week's U.N. session, Iranian-Americans marked the anniversary of the 1988 mass execution of 30,000 political prisoners.

U.S. officials are charging Afghan-born bombing suspect Ahmad Khan Rahami with planting a series of bombs in New York and New Jersey over the past three days. This follows the FBI's admission earlier on Tuesday that it looked into Rahami's activities two years ago when they carried out an assessment of him. This based on a tip from his father who told agents at the time that he was concerned about his son's possible involvement with extremists. They found insufficient evidence to launch an investigation.

This is VOA news.

"Not dead yet." That's the assertion of several key diplomats about the cease-fire in Syria following the attack on an aid convoy on Monday.

The 20 members of the International Syria Support Group met for about an hour on Tuesday in New York and decided to convene again on Friday.

It is widely believed an airstrike was carried out either by Syrian or Russian aircraft on an aid caravan that was heading to the Syrian city of Aleppo. The attack killed 20 civilians and the head of a local office of the Syrian Red Crescent.

The White House on Tuesday evening pinned the blame squarely on Moscow for imperiling the cease-fire and for the attack on the aid convoy which national security adviser Ben Rhodes called an "enormous humanitarian tragedy."

John Kirby, the U.S. State Department spokesman, said they "agreed, despite continued violence, there was still an imperative to pursue a nationwide cessation of hostilities."

The mood is tense in the Democratic Republic of Congo, following a day and night of deadly violence involving security forces and anti-government protesters. A human rights group reports that a total of more than 40 people have been killed, most of them civilians. William Clowes reports from Kinshasa.

There were sporadic clashes between police and groups of young men early Tuesday in some parts of the capital. Unusually for Kinshasa, trucks full of soldiers from the Republican Guard were out on the streets

Heavier violence took place overnight as armed men set fire to at least five headquarters of opposition parties.

Felix Tshisekedi, a leading figure in the largest opposition party, the UDPS, spoke to reporters Tuesday.

Tshisekedi went on to say that the DRC is a dictatorship and he says this government deserves the popular revolt that is coming to topple it.

He later told VOA by phone that the death toll from the overnight attack has risen to seven and others are still missing.

William Clowes, for VOA news, Kinshasa.

In American politics, the first face-to-face debate between Republican candidate Donald Trump and his Democratic rival, Hillary Clinton, is set for next Monday.

On Tuesday, the moderator of that debate has revealed the topics to be discussed.

VOA's Esha Sarai has more.

The debate will consist of two 15-minute segments for each of the three following topics: America's direction, achieving prosperity and securing America.

Third-party candidates Jill Stein and Gary Johnson were not invited to the debate as they did not reach the required threshold of support by averaging at least 15 percent in five public opinion polls selected by the Commission on Presidential Debates last month.

Esha Sarai, VOA news.

For more on this and other top stories, visit us online at voanews.com. Reporting from Washington, I'm Steve Karesh.

That's the latest world news from VOA.