Negotiated by world and regional powers late last year, the first UN-sponsored talks between Syrian government and opposition forces were initially scheduled to be held on Monday.
"We are not against one or two delegations [from the opposition], but it is important for groups from Riyadh, Moscow and Cairo to be equal," Qadri Jamil told reporters at the Rossiya Segodnya International Information Agency.
Jamil, one of the leaders of the Popular Front for Change and Liberation that holds five seats in the Syrian legislature, has regularly accused Saudi Arabia of attempting to hijack the list of opposition delegates at the much-anticipated talks.
Damascus said last month it did not recognize the Saudi-backed opposition, who demand the resignation of President Bashar Assad, and vowed to treat them as terrorists.
"The UN Security Council’s resolution 2254 was adopted to implement [these talks]. I do not think that the Security Council will take the liberty of not implementing its resolutions, as this undermines its credibility," Qadri Jamil said.
The Syrian politician also expressed confidence that the intra-Syrian talks would begin this month, as previously announced by the United Nations.
Syria has been in a state of civil war since 2011, with forces loyal to President Bashar Assad fighting several opposition factions and numerous extremist groups.