Syria's opposition chief on Sunday (January 6th) urged Arab leaders not to rebuild relations with President Bashar al-Assad's government, voicing frustration amid apparent efforts to bring the Damascus regime back into the Arab fold, AFP reported.

After years of frosty ties, the UAE last month reopened its embassy in the Syrian capital, and fellow Gulf state Bahrain has followed suit.

"We are surprised that our brothers are reaching out and building relations with this regime," opposition leader Nasr al-Hariri told reporters in Riyadh, where he lives in exile.

"We hope that our brothers, the leaders of Arab nations, will not abandon the Syrian people," he added, urging them to reconsider their decisions.

Almost eight years into Syria's war, opponents of al-Assad’s regime are watching in dismay as his government looks set to secure a comeback.

With backing from Russia and Iran, the government has expelled opposition and extremist fighters from large parts of Syria, and now controls almost two-thirds of the country.

The Arab League suspended Syria's membership in November 2011.

Most Gulf states closed their embassies in 2012.

But several Arab states are seeking to restore ties with al-Assad after his forces made decisive gains in the war, in a bid to expand their influence in the country.