Malaysian Prime Minister Najib Razak on Thursday dismissed calls for him to step aside over a political funding scandal, vowing to continue to lead the country's beleaguered ruling party.

"Even though there are traitors, and no matter how many times we are pushed to the ground, there shall be no retreat, no surrender," Najib told more than 2,000 delegates to the United Malays National Organisation's (UMNO) annual assembly.