Real political will from all sides is needed to end the 18-monthSyrian crisis, a senior adviser to Syrian President Bashar al-Assad said.

In an exclusive interview with Xinhua, Bouthaina Shaaban, Assad's special envoy and political and media advisor, said the reason a ceasefire didn't happen despite UN-Arab Leaguejoint envoy Kofi Annan's persistent efforts was the lack of real political will, especially on the Western countries' side.

"The Western forces led by the U.S. say that we support the six-point plan of Kofi Annan, but in reality they support or they allow other countries also to support the armed groups with weapons and money," Shaaban said.

"Hence, there is a contradiction in this," Shaaban said, blaming Western countries for acting "exactly against the plan."

To achieve solidarity in the international community over the Syrian issue, according to the 59-year-old former Syrian Minister of Expatriates, would depend on whether the West was ready to sit around the table withRussiaand China, the two countries that "supported in word and in action the Kofi Annan plan."

"We as Syria's government are ready to engage in any dialogue. But it is the opposition who would not (be) ready and who all the time announce that they will not engage in a dialogue with the Syria government," Shaaban said.

She urged western powers to stop aiding the armed rebels and instead press them to start immediate dialogue with government forces.

"And if there is a political will on the Western countries' side, then everybody will sit around the table and it will be easy to find a roadmap to get out of the Syria crisis," she said.

On Thursday, Shaaban met Chinese Foreign Minister Yang Jiechi here for talks, in which Yang urged both the Syrian government and the opposition to coordinate with international mediation efforts to end the crisis quickly.

Shaaban pledged the Syrian government was ready to work with relevant parties to seek ways for a ceasefire, and begin an inclusive dialogue with the opposition to promote a Syria-led political process and restore security and stability in the country.

On the U.N. mission in Syria, Shaaban said the Syrian government supported the UN role in Syria and any "formula" it wanted to employ.

It also supports veteran Algerian diplomat al-Akhdar al-Ibrahimi, who succeeds Annan as the new UN envoy to Syria, Shaaban said.

She stressed international coordination as a cornerstone for the UN mission in Syria to succeed.

"If you notice what al-Akhdar al-Ibrahimi said, that, in order to succeed, he needs the international community to agree on a course of action in Syria, and I agree with that, that the international community should agree on supporting mediation and supporting a political solution," she said.

However, some Western and Arab nations were apparently "destabilizing Syria by providing money and armaments to armed groups who committed the most horrible crimes," although they pledged support for Annan's peace plan, she said.

She urged those countries to "truly support the UN mission," like Russia, China,Iranand the Syrian government, to make it a success.

Asked whether there would be a no-fly zone over Syria, as some western countries proposed, Shaaban said that would be "considered as an aggression against Syria.

"Syria is a country that will not accept any aggression and will defend itself," said Shaaban, who has served as Assad's political and media adviser since 2008.

The envoy also denied any possibility of a no-fly zone established under a different guise in the future: "I don't think so ... And I hope this will never be agreed upon."

On political reforms, Shaaban said the Syrian government is "pressing ahead with reforms, despite the fact that economic sanctions and armed rebels are of course making us pay a heavy price."

"But no matter what happens in the country, we are pressing ahead with our reforms," she said.