"Resistance (to Israeli "occupation") forms the core of our policy, both in the past and in the future. We do not put forward conditions on making peace, but we do have rights that we will not renounce," he told a meeting of Arab political parties in Damascus.
Israel captured the Golan Heights from Syria in the 1967 Middle East war and unilaterally annexed it in 1981. Damascus has repeatedly demanded the strategic plateau's return as a non-negotiable condition for peace.
"If we are strong we will achieve the peace we seek. Resistance is at the heart of the new Middle East we have begun to build," Assad said.
On Monday the Syrian president warned that if the Golan Heights are not returned peacefully – Syria will turn to resistance. Speaking at an economic forum of the Organization of Islamic Conference in Istanbul, Assad said, "The failure of negotiations towards the full restoration of rights automatically means resistance is the alternative solution."
Last year, Turkey brokered four rounds of indirect talks between Israel and Syria, focusing on the key Golan issue.
But the talks were suspended when the Jewish state waged an offensive against the Palestinian Hamas rulers of the Gaza Strip over the new year.
On a trip to Croatia last month, Assad said Syria was ready to resume talks with Israel and called on European nations to help in the process.
"We call on European countries to also give their contribution, to help Turkey but also us to be able to resume from where we have stopped," he said.
In response, Israeli Defense Minister Ehud Barak said the Jewish state was ready to try to make progress towards making peace with Syria if Damascus and its allies took a "responsible" stand.
Roee Nahmias contributed to the report