Damascus, Syria (CNN) -- North Korea requested permission from Iraq this week to fly a plane through its airspace to Syria, an adviser to Iraqi Prime Minister Nuri al-Maliki told CNN on Friday.
Al-Maliki rejected the request out of suspicion the plane would be carrying weapons, said adviser Ali al-Mousawi.
The prime minister talked by phone with U.S. Vice President Joe Biden on Friday afternoon, officials said.
Biden asked Iraq for help in stopping weapons from reaching Syria, according to a statement released by his office, and stressed to the Iraqi prime minister "the need to prevent any state from taking advantage of Iraq's territory or airspace to send weapons to Syria."
Al-Maliki "expressed the Iraqi government's discomfort with some informal U.S parties of stirring suspicions about Iraq's position toward the Syrian crisis," and that Iraq has held a "firm position in rejecting any weapon supplies or violent activity over Iraq's territories or its airspaces," according to a release from his office.
"Al-Maliki reiterated the position of the Iraqi government based on the need to find a peaceful political solution for the Syrian crisis and its rejection to supply ammunitions to any party involved in the Syrian conflicts," the release said.
Opponents of Syrian President Bashar al-Assad's rule are concerned about the shuttling of arms to his government by entities such as Iran. Iraq borders Syria and Iran.
Al-Assad magazine interview
Earlier, Syria's besieged president slammed the rebels battling his government forces, but said the "door to dialogue is open."
"Dialogue with the opposition is the only way out to address the crisis," al-Assad said in a magazine interview published Friday.
The cries for freedom and democracy that spread across the Arab world last year also reached Syria. That set the wheels in motion for a standoff that morphed into a civil war between the al-Assad government and a burgeoning rebel movement.
More than 26,000 people, mostly civilians, have been killed in the one-and-half-year-long conflict, according to opposition activists.
Al-Assad, who blames the violence on terror groups, told Egypt's Al-Ahram al-Arabi magazine that "armed men are engaged in terrorism against all of the state's institutions."
"They have no support in the society. Rather, they have harmed the interests of the people by targeting the infrastructure that serves the people and killing innocent Syrians. Ultimately, they will not emerge victorious," he said.
He said backers of these forces "think the only solution is through a Libyan scenario." That's a reference to rebel forces, with foreign backing, toppling Libyan dictator Moammar Gadhafi and his government.
"But a decisive end (to the crisis) will take some time, of course. However, the door to dialogue is open and we have offered several initiatives for amnesty for all of those who put down their arms in order to encourage dialogue," al-Assad said.
The president took jabs at Saudi Arabia, Turkey and Qatar -- all supporters of the opposition.
"They suddenly saw money in their hands after a long period of poverty and think they can change (the role of) history and geography, and play a regional role," al-Assad said, referring to Saudi Arabia and Qatar.
Before the Syrian conflict started last year, Saudi Arabia served only as a "mediator with the West that does not appreciate the axis of resistance against Zionism advocated by Syria," the president said.
"Let me correct a prevalent idea that Saudi Arabia, Syria and Egypt are the triangular axis of stability in the region. This is not true. It has always been, and will remain, Syria, Iraq and Egypt," he said.
As for Qatar, it "uses the power of money and revolves in the orbit of the West by providing weapons and money to terrorists to repeat the Libyan scenario," al-Assad said. And Turkey, he said, has "lost a lot" by taking its stance on Syria.
"They are unconcerned about the interests of its people, focusing solely on its ambitions that include the new Ottoman Empire," he said.
Here's a roundup of other developments in Syria's conflict:
Mass grave, massacres reported in Damascus area
Twenty-five "bound and blindfolded" bodies were found in a mass grave in the al-Qadam area of Damascus Friday, Syria's state news agency said. Authorities blamed the deaths on "armed terrorist groups."
The government also said its armed forces "killed a number of terrorists" in the Damascus area town of Beit Jen.
The opposition Local Coordination Committees of Syria said regime forces conducted a "massacre" in the suburb of Buwaida. Seventeen people were stabbed to death after soldiers stormed the area, it said.
The LCC said the 17 were among 117 people killed across Syria on Friday. Forty-eight deaths occurred in the Damascus area. Seventeen people were killed in Aleppo and 15 each in Homs and Idlib provinces. Violence also raged in Daraa, Raqqa, Deir Ezzor, Latakia and Hama provinces.
Opposition figures disappear upon arrival in Syria
Two members of the National Coordination Body for Democratic Change -- an opposition group -- and a friend who came to pick them up disappeared shortly after leaving the airport in Damascus, the group said.
"The National Coordination Body's Exile Branch holds the kidnappers, whoever they be, completely responsibility -- ethically, legally, and politically -- for any physical or mental harm done. We demand an explanation for why there has been no communication, whatever the motives and reasons. We demand they be immediately returned safely to their families," the NCB said in a statement.
Syrian state news blamed terrorists for kidnapping the men.
Help for Syrians
The U.N. refugee agency says it is making progress relocating Syrian refugees in Lebanon.
It is also working to enroll refugee children in Lebanese and Iraqi schools, the agency said Friday. Nearly 73,000 Syrian refugees in Lebanon have registered or are awaiting registration with the United Nations. There are now more than 29,000 Syrians in Iraq.
A second Russian plane transporting 38 tons of food arrived in Damascus Friday, according to the Syrian Arab News Agency, which reported the arrival of a similar shipment Thursday.
CNN's Mohammed Tawfeeq reported from Baghdad and Nic Robertson reported from Damascus. Hamdi Alkhshali, Amir Ahmed and Joe Sterling contributed to this report from Atlanta.