The European Union will freeze the assets of the Syrian Central Bank to further pressure President Assad's regime to stop violence against civilians, news agency reports suggest.
Reuters said that the EU will impose the ban on 27 February, quoting French foreign minister Alain Juppe.
Speaking at the Friends of Syria conference in Tunis, US Secretary of State Hilary Clinton called on all nations to follow suit.
She said: "It's time for everyone here to place travel bans on senior members of the regime - as the Arab League has done - freeze their assets, boycott Syrian oil, suspend new investments, and consider closing embassies and consulates."
The Arab League, United States, UK, France and Turkey are all in attendance at the Friends of Syria meeting in Tunisia, in an attempt to find a way to end the violence.
At the meeting calls were made by the Qatari prime minister Hamad Bin Jassim for an Arab League military force to impose peace in the country.
He said: "There is a need to create an Arab force and open humanitarian corridors to provide security to the Syrian people."
Tunisian president Moncef Marzouki suggested that President Bashar al-Assad and his family could be granted immunity in order to encourage him to step down.
Foreign Secretary William Hague told reporters the Syrian government is now a "criminal regime".
Hague said that he now recognised the opposition Syrian National Council (SNC) as "a legitimate representative of the Syrian people".
"I think we have seen enough in the last few weeks to know that the Assad regime will go down in history as a criminal regime.
"The United Kingdom will continue our work to help document the crimes that are taking place so that one day those responsible for them will have to answer for their actions."
The foreign secretary also called on China and Russia, who have consistently voted against condemnation of Syrian President Bashar al-Assad' regime in the United Nations, to change their position.
"I hope those countries will take note of this strength of international feeling and support that we're seeing here in Tunisia with more than sixty countries coming together," he told reporters. "Because it means that they are increasingly isolated in their view."
"It's very important for Moscow and Beijing to a re-evaluate their position".
Neither Russia or China are attending the 70-nation Friends of Syria meeting organised by the Arab League.
Earlier Russia issued a statement calling for an immediate ceasefire in the country on both sides, calling on other countries to more strongly condemn the actions of the armed opposition as well as the government.
Hague stopped short of acceding to demands made by opposition fighters for more arms to be brought into the country, saying that the EU had to recognise its arms embargo "in all directions".
The SNC insisted it needed the means to defend itself.
It said in a statement: "If the regime fails to accept the terms of the political initiative outlined by the Arab League and end violence against citizens, the Friends of Syria should not constrain individual countries from aiding the Syrian opposition by means of military advisers, training and provision of arms to defend themselves."
Reuters < a href="http://www.reuters.com/article/2012/02/24/us-syria-idUSL5E8DB0BH20120224?feedName=worldNews&feedType=RSS">reported that foreign nations are already "turning a blind eye" to imports of weapons, communication systems and night vision goggles.
"We are bringing in defensive and offensive weapons... It is coming from everywhere, including Western countries and it is not difficult to get anything through the borders," an anonymous opposition source told the news agency.
Other opposition drops have boycotted the meeting, according to the AFP, including the National Co-ordination Committee For Democratic Change.
They say that the meeting leaves open the possibility of military intervention.
It was also reported that a group of pro-Assad protesters had broken into the grounds where the meeting its taking place.
Meanwhile activists reported continuing violence across Syria after around 100 people were killed on Thursday.
Up to 9,000 people have died since the start of anti-government protesters in March 2011, activists have said.
The Syrian government insists the violence is mainly the result of "armed terrorist groups".