Russia has proposed that the United Nations Security Council blacklist Syrian rebel groups Jaish Al-Islam and Ahrar Al-Sham because of their links to the Islamic State and Al-Qaeda terrorist groups.
Russia's proposal to the council's Islamic State and Al-Qaeda sanctions committee on April 27 will go into effect on May 11 unless other nations represented on the 15-member committee block it, UN diplomats said.
"The reason for such a move was the information that these groups, which are waging a war in Syria, are closely connected to terrorist organizations, first of all with [IS] and Al-Qaeda," Russian UN Ambassador Vitaly Churkin said.
Washington's mission to the UN cautioned against blacklisting the two groups, however, saying it would undermine attempts to get a sustained cessation of hostilities in Syria.
"Designating Jaish Al-Islam and Ahrar Al-Sham -- two groups that are parties to the cessation of hostilities -- would have damaging consequences to the cessation just as we are trying to deescalate the situation on the ground," Edgar Vasquez, a spokesman for the U.S. mission, said.
One UN diplomat told the Reuters news agency that Russia's move is aimed at "dividing the opposition" and weakening the opposition's hand in UN-sponsored negotiations with the Syrian government, Moscow's ally.
But Churkin disputed that the groups have been honoring the cease-fire or contributing to the peace talks in Geneva.
"The time has come to call things by their true names," he said. Blacklisting the groups would make them ineligible to participate in either the cease-fire or peace talks in the future.
Russia's Foreign Ministry has long said that Jaish Al-Islam and Ahrar Al-Sham should not be involved in Syria peace talks because of their ties to banned terrorist groups.
Jaish Al-Islam (Army of Islam) is a major armed rebel group in Syria and is currently a member of the High Negotiation Committee, a coalition of rebel groups formed in Riyadh last December to negotiate for the opposition in the talks.
The High Negotiation Committee is backed by Western nations as well as Saudi Arabia and other Arab states, but it recently suspended participation in the peace talks because of alleged violations of the cease-fire by the Syrian regime.
Ahrar Al-Sham never joined the coalition, contending that "revolutionary groups" were sidelined at the Riyadh meeting. But the group did attend this month's round of peace talks.
Ahrar Al-Sham is an ultraorthodox Salafist group and has fought as part of a military alliance with the Al-Nusra Front, Al-Qaeda's affiliate in Syria.
Ahrar Al-Sham's late leader fought alongside Osama bin Laden, but the group has denied sharing Al-Qaeda's ideology or organizational ties.
With reporting by Reuters and TASS