The fate of Syrian President Bashar Assad is sealed, according to Abdullah Gül, the president of Turkey, which until recent months had forged a warm relationship with Syria and Iran.

“Some think that we want war in Syria. Turkey has done everything in its power for a transformation under the leadership of the president. We did everything except beg for it,” he told reporters in remarks published by Turkish newspapers Tuesday.

“We worked so hard [to convince Assad]. We told him that one day you will regret it, one day you will say, ‘I did this and that,' but it will be too little, too late,” said Gül, quoted by Today’s Zaman.

“We regret this, but Syria is unfortunately on a path of no return. The important thing is that this process is not dragged out. There is no [good] end for this. The end is certain. The question is how painful it will be,” the president also said.

He also said that ”foreign intervention will be inevitable” if Assad does not institute reforms instead of continuing the daily slaughter of civilian protesters and army deserters.

Pressure is mounting on Russia not to thwart new efforts to sanction Syria in the United Nations Security Council. British Prime Minister David Cameron called on “all the members of U.N. Security Council to live up to their responsibilities instead of shielding those who have blood on their hands.”

"Russia can no longer explain blocking the U.N. and providing cover for the regime's brutal repression," the prime minster’s spokesman said.

U.S. Secretary of State Hillary Clinton said on Monday, “The status quo is unsustainable” and the volatility in Syria could "spill over throughout the region.”

Syrian forces on Tuesday continued to kill opponents and soldier-turned-rebels, who have breached the suburbs of Damascus, previously totally loyal to Assad. Government-controlled media said the army "chased the elements of armed terrorist groups that committed the worst crimes of murder and kidnapping against the citizens and had planted mines on public roads and terrorized people, including children and women” in the capital’s suburbs.

The government also claimed it had confiscated Israeli and American weapons from the opposition fighters.