A "full-scale civil war" in Syria is now a real possibility, British Prime Minister David Cameron warned after talks with Turkish President Abdullah Gul in London Tuesday, dpa reported.
Cameron urged international leaders to exert "concerted pressure" on the regime of Syrian President Bashar al-Assad, and to engage with opposition groups in the Middle Eastern country.
The escalating violence in Syria and the renewed turmoil in Egypt were at the centre of talks between Cameron and the Turkish president, who arrived in Britain on a three-day state visit Tuesday.
"Today we had important discussions on Syria, where now a full-scale civil war is a real possibility," said Cameron.
He called for "concerted pressure" on the regime and "positive engagement with the opposition, who can represent Syria in an inclusive transition."
Cameron praised the efforts of Turkey and the Arab League, which he said had shown "welcome leadership and given us a way to stop the brutality of this morally bankrupt regime."
The situation in Libya, Afghanistan and Iran was also discussed, a spokesman said.
Gul and his wife Hayrunsia were earlier given a full military welcome in London by Queen Elizabeth II, who is hosting the couple at Buckingham Palace.
In an interview with the BBC, Gul said the Syrian regime had reached a "dead end" and was now facing a "worst case scenario."
"In this age, authoritarian regimes or one-party states are no longer acceptable," he said.
Turkey's long struggle for full membership of the European Union (EU), which is backed by Britain, was also discussed, with both sides advocating the mutual extensions of trade ties, officials said.
In an interview with the Sunday Telegraph newspaper published ahead of the visit, Gul warned Western countries against adopting a "narrow scope" on the question of Turkey's EU membership.
"Those who can think 30 years, 60 years ahead, and who can think about the changing trends in the economy and the changing centres of power, can understand how much strength Turkey can bring to the existing strength of Europe," he said.
The president and his wife will also visit the Olympic Park in east London, where next year's Olympic Games will be held, before returning to Ankara on Thursday. The queen made a state visit to Turkey in 2008.