Arab diplomats have said the US has asked Arab nations to amend the 2002 land-for-peace proposal to make it more palatable to Israel.
Foreign Minister Walid al-Moallem also told reporters Thursday before meeting two US envoys that Damascus is still testing American intentions toward his country.
The top US diplomat for the Middle East, Jeffrey Feltman, and National Security Council member Daniel Shapiro are in Damascus for the second time since March, signaling the Obama administration's efforts to explore ways to improve relations with a country Washington has criticized as a state sponsor of terrorism.
The foreign minister's statements came a day after al-Quds al-Arabi newspaper quoted Palestinian sources as saying that the leaders of Egypt, Jordan, Saudi Arabia and the Palestinian Authority have been working on a "clearer" initiative at the request of US President Barack Obama.
The Arabs are working vigorously so that Egyptian President Hosni Mubarak will be able to present the revised proposal to Obama during their upcoming meeting in Washington.
According to the sources, the new initiative will call for the settling of Palestinian refugees in Arab countries and in a future Palestinian state, following a land swap with Israel.
The US administration has also demanded that the Arab countries set a timetable for the normalization of their ties with Israel with the aim of encouraging Jerusalem to take practical steps towards the establishment of a Palestinian state, they added.
Roee Nahmias contributed to this report