BRUSSELS, Belgium — Moscow and Beijing remain opposed to any foreign interference in Syria, the Foreign Ministry said Thursday as Russia worked to shore up international support for its position ahead of a major international conference.

Russia and China have vetoed two Security Council resolutions backing Arab League plans aimed at ending the conflict in Syria and condemning President Bashar Assad's brutal crackdown on opponents. Thousands of people have been killed since an uprising began in March.

Foreign Minister Sergey Lavrov's office said he called his Chinese counterpart on Thursday and they "reaffirmed the joint position of Russia and China."

Both countries support "a speedy end to any violence in Syria and the launch of inclusive dialogue between the authorities and the opposition without preconditions for a peaceful settlement that excludes foreign interference in Syrian affairs," the ministry said.

Officials from the United States, Europe and Arab nations were meeting in London on Thursday to craft details of an ultimatum to Assad demanding that he agree to a cease-fire and allow humanitarian aid into areas hardest hit by the crackdown.

The ultimatum was to be presented at a major international conference Friday in Tunisia on the Syrian conflict.

Russian President Dmitry Medvedev also continued his efforts to build support for Russia's position. The Kremlin said he spoke by telephone Thursday with the president of the United Arab Emirates, following up his calls the day before to the leaders of Saudi Arabia, Iran and Iraq.

Medvedev emphasized that "foreign interference, attempts to assess the legitimacy of the leadership of a state from the outside run counter to the norms of international law and are fraught with the threat of regional and global destabilization," the Kremlin said.

Russia and China are eager to head off any repeat of what happened in Libya.

Last year, the U.N. Security Council invoked "the responsibility to protect" when it established a no-fly zone over Libya. Russia and China abstained from that decision and strongly criticized Western governments' interpretation of the U.N. mandate, which led to a monthslong NATO bombing campaign against Libyan military facilities.

Meanwhile, the Federation of Jewish Communities in Russia on Thursday condemned a Kremlin decision to give a state cultural award to a Syrian writer known for his anti-Semitic views.

Ali Ukla Ursan was among about a dozen foreigners who received an award from Medvedev during a ceremony on Feb. 17. In accepting the Pushkin Medal, Ursan thanked the president for Russia's "wise policies" in Syria, according to a Kremlin transcript.