DAMASCUS - As the UN and the Syrian government were still wrangling about an extended international probe of alleged usage of chemical weapons in northern Syria, the Iraqi wing of al-Qaida terror network announced Tuesday its mergence with radical Nusra Front currently operative on Syrian soil.

UN Secretary-General Ban Ki-moon urged the Syrian government to "extend its fullest cooperation" to allow an extended investigation of alleged usage of chemical weapons across Syria. He also said he wanted to investigate another attack in Syria's central Homs province that allegedly took place on Dec 23.

Ban's new remarks were made in Rome Tuesday, a day after the Syrian government objected the UN's desire to conduct an extended probe.

The Syrian Foreign Ministry said Monday that the UN request to conduct a full investigation about chemical weapons on all Syrian territories runs counter to the request of the Syrian government.

Damascus has asked the UN to send a technical team to the northern town of Khan al-Asal to investigate a chemical attack for which the government blamed on rebels. More than 50 people were killed and scores of others are in hospital. Syria stressed the technical team should work only at the targeted site. But the opposition groups have called on the UN to conduct a full investigation.

The government's response came after Ban stated that inspectors were ready to deploy a mission within 24 hours to investigate reported chemical weapon attacks across the country.

Syria's Foreign Ministry said it regrets Ban's "submission to pressure by some countries well known for their support to bloodshed" in Syria.

"Syria doesn't accept such maneuvers," the ministry said, reasserting that Syria was still ready for cooperation with the UN to send investigators immediately to Khan al-Assal.

While this drags on, the Iraqi wing of the al-Qaida declared Tuesday that it was unifying ranks with the Syria-based al-Qaida- related Nusra Front.

The declaration came Tuesday in an online video by Abu Bakr Baghdadi, identifying himself as the leader of the Islamic State in Iraq.

The declaration came to add to the fears of the Syrians as well as the West that has been backing the opposition in Syria since the beginning of crisis in March 2011 that their country might plunge in a quagmire akin to that in Afghanistan and Somalia, which have been suffering from the rules of radical groups.

The Nusra has claimed responsibility for most of the bombing across Syria as such tactics are considered typical of al-Qaida- like mindsets. The Syrian government has repeatedly warned about the growing danger of such groups not only on Syria but the entire region.

The Syrian Foreign Ministry also stressed Tuesday that the suicide bombings and mortar shells that have lately targeted residential areas in Damascus and other Syrian cities would not prevent the Syrian administration from continuing its combat of terrorism.