US Vice President Joe Biden urged Syria's Bashar Al-Assad to quit, in a Turkish newspaper interview published Friday, adding to growing global pressure on the regime over its crackdown on dissidents.
"The United States' position on Syria is clear. The Syrian regime must end its brutality against its own people and President Assad must step down so a peaceful transition that respects the will of the people can take place," Biden told the Hurriyet daily.
The vice president, who arrived in Ankara late Thursday directly from an Iraq visit, called for a peaceful transition in Syria where the regime's crackdown has claimed more than 4,000 lives according to the United Nations.
"Syria's stability is important. That is exactly why we are insisting on change -- it is the current situation that is unstable," Biden said in response to emailed questions from the daily.
"Lasting stability can come when there is a government that listens to its people and addresses their needs, rather than turning their guns on them."
Europe and the United States tightened economic sanctions on Syria Thursday, including bans on exporting gas and oil industry equipment and trading Syrian government bonds in an effort to choke off funding.
Biden praised Turkey's "real" leadership on Syria.
"Turkey has been a real leader on this issue. I commend Prime Minister Erdogan's recent call for Mr Assad to step down because of the regime's treatment of its people, as well as Turkish leaders' calls for others in the international community to support the Syrian people," he said.
The United States and its Western allies are leading a campaign to isolate Assad over the bloody crackdown.
Turkey, a traditional NATO ally of Washington, announced tough sanctions on the Syrian regime, including a freeze on commercial transactions and a break in links with the Syrian central bank.
Ankara also hosts Syrian army defectors and an umbrella opposition group: the Syrian National Council.
"We also welcome the government's giving space in Turkey to the political opposition," said Biden.
"It is time for all in the international community to join in isolating a regime that has systematically violated human rights and repressed peaceful protests," he added.
"We look forward to the broadening of international sanctions as a means to bring about change in Syria."
Several countries, including Turkey, have raised fears that Syria is sliding towards civil war.
"Civil war is the last thing that we would want to see in Syria," Turkish President Abdullah Gul was quoted as saying by the private NTV television. Biden met Parliament speaker Cemil Cicek and Gul Friday for talks also focused on Turkey's fight against Kurdish rebels based in northern Iraq and the row over Iran's disputed nuclear programme.
He said Washington and its European allies would "continue to keep the pressure" on the rebel Kurdistan Workers' Party (PKK), listed as a terrorist group by Turkey, the US and the European Union.
On Iran, Biden encouraged Ankara to impose sanctions alongside efforts for a negotiated settlement.
"We continue to support a diplomatic solution to our concerns with Iran," he said.
"However, we also believe that putting pressure on Iran's leadership is necessary to secure a negotiated settlement, and that is why we encourage our partners, including Turkey, to take steps to impose new sanctions on Iran, as we have continued to do."