According to Kaja Kallas, the meeting of the EU foreign ministers will take place in Brussels on January 27.
After 13 years of civil war, Syria's President Bashar al-Assad was ousted in a lightning offensive by insurgent forces led by the Islamist Hayat Tahrir al-Sham (HTS) a month ago. The group has since set up a caretaker government in Damascus.
Any European decision to ease sanctions would be conditional on the new Syrian administration's approach to governing, which must include "different groups" and women and "no radicalisation", Kaja Kallas said.
"If we see the developments going to the right direction, we are ready to do the next steps...If we see that it's not going to the right direction, then we can also move back on this."
Sunday's conference, the first such meeting of Western and regional leaders hosted by regional heavyweight Saudi Arabia since Assad's ouster, comes as Damascus urges the West to lift sanctions to help international funding flow more freely.
In a press conference held after wrapping up the conference, Saudi foreign minister Prince Faisal bin Farhan Al Saud said he stressed "lifting the unilateral and U.N. sanctions imposed on Syria as continuing ... sanctions will hinder the aspirations of the Syrian people to achieve development."
Strict sanctions on Syria
The U.S., Britain, the European Union and others imposed tough sanctions on Syria after a crackdown by Assad on pro-democracy protests in 2011 that spiralled into civil war. But the new reality in Syria has been complicated by sanctions on HTS - and some leaders - for its days as an al Qaeda affiliate.
Germany, which is leading the EU's discussion on sanctions, on Sunday proposed allowing relief for the Syrian population, but retaining sanctions on Assad allies who "committed serious crimes" during Syria's war.
"Syrians now need a quick dividend from the transition of power, and we continue to help those in Syria who have nothing, as we have done all the years of civil war," German foreign minister Annalena Baerbock told reporters in Riyadh.
The United States on Monday issued a six-month exemption of its sanctions for transactions with governing institutions in Syria to try to ease the flow of humanitarian assistance and allow some energy transactions.
British foreign minister David Lammy joined the Riyadh talks along with ministers from Saudi Arabia, Egypt, the United Arab Emirates, Qatar, Bahrain, Iraq, Jordan, Lebanon and Turkey, as well as the U.N. special envoy for Syria, Geir Pedersen.
Discussions would focus on support for the interim Syrian authorities, "including mechanisms to hold the Assad regime to account for the war crimes they perpetrated against the Syrian people," the UK foreign office said in a statement.
