George Mitchell, President Barack Obama's Middle East envoy, said the US sought what he described as comprehensive Middle East peace that included a deal between Syria and Israel and the normalisation of relations between the two foes.
"Syria, certainly, has an important role to play in all of these efforts... and that was the topic of our discussion today," Mitchell said in a brief statement.
He said he looked "forward to making tangible progress on our efforts toward peace and on the bilateral relations between the United States and Syria".
Ties between Syria and the United States improved after President Barack Obama took office and Mitchell met Assad twice last year. Deputy Foreign Minister Fayssal al-Mekdad, a leading figure in Syrian foreign policy, also visited Washington.
Differences, however, persisted.
Damascus has not hidden its frustration with the pace of ties with Washington. Syrian officials have said Obama should lift sanctions first imposed in 2004 for its support of militant groups and exert pressure on Israel to renew the peace talks.
The indirect talks, which were mediated by Turkey, broke down during the Israeli offensive on Gaza a year ago without defining the boundary of the Golan Heights, the Syrian plateau that Israel occupied in the 1967 Middle East War.
The official Syrian news agency said Assad told Mitchell that Turkey had an "important role" to play in reviving the talks and Israel had to "declare frankly" that it wants peace.
Syria improved its ties with Turkey as tension mounted between Ankara and Israel during the past few months, which made Israeli officials wary of Turkey resuming a mediation role.
Syria wants an Israeli commitment to withdraw from the whole of the Golan based on a UN resolution stating the inadmissibility of the acquisition of territory by force. Israel said it was willing to resume the talks without preconditions.
Israel and its chief ally, the United States, want Syria to cool its ties with Iran as well as stop supporting the Palestinian Islamist group Hamas and Lebanon's Hezbollah movement, and help sideline them as armed players.
A Syrian source said Assad would continue to show flexibility with Washington but only up to a point.
"The late Hafez al-Assad used to say that the Americans want us to commit suicide. Bashar has limits to what he can give the United States," the source said.
Bashar succeeded his father, the late President Hafez al-Assad, in 2000, months after the elder Assad, who ruled Syria for three decades, rejected a US-supervised deal that did not restore what he considered as a the whole of the Golan.