BEIJING, SEPT. 30 -- A senior Foreign Ministry official said this evening that China would approve an arms embargo against Iran and Iraq if United Nations mediation efforts failed.

But senior Vice Foreign Minister Qian Qichen said China favored further diplomatic efforts by U.N. Secretary General Javier Perez de Cuellar before approving an embargo.

"As for an arms embargo, there is no problem with the Chinese," said Qian in answer to questions from foreign reporters at a reception on the eve of China's national day.

Given China's good relations with Iran, some observers said earlier they doubted China would go along with such a proposal.

Qian Qichen's comments were the first clear public statement to foreign reporters from a ranking Chinese official that the Chinese could agree to an arms embargo.

A western diplomat said Qian's statement was consistent with what the Chinese have been saying for some time at the United Nations and in private talks concerning the seven-year-old Iran-Iraq war.

As a permanent member of the U.N. Security Council, China has been playing an active diplomatic role in attempting to end the war.

But the western diplomat also said that China's position on an arms embargo appeared to contradict its record of selling arms to Iran.

The Chinese are believed to be major suppliers of arms to Iran, and U.S. officials have accused them of selling that country Silkworm coastal defense missiles that could be used to threaten shipping in the Strait of Hormuz.

Chinese Premier Zhao Ziyang said in an interview with NBC News Friday that China will try to prevent exports of Chinese arms to other countries from reaching Iran or Iraq. But contrary to U.S. allegations, Zhao said he did not believe the missiles Iran has are of Chinese origin.

Western diplomats said this week that they were still not certain whether China had stopped selling arms to Iran.

China has declared itself neutral in the Iran-Iraq war and has consistently denied selling weapons to either side.