CHINA and France have vowed to restore their friendly ties strained over the French sale of weapons to Taiwan after Paris undertook not to authorise any French firms to trade military arms with the island, it was announced yesterday. According to a joint communique issued by Xinhua (the New China News Agency), French Prime Minister Edouard Balladur is to pay an official visit to China. It is reported that the visit starts on January 27, the 30th anniversary of the establishment of Sino-French diplomatic ties. The trip was the result of secret talks between a French government envoy, Jacques Friedmann, with senior Chinese leaders including Premier Li Peng and Vice-Premier Qian Qichen in Beijing last month. Top-level dialogue between Beijing and Paris was halted in 1992 when France agreed to sell Mirage 2000-5 fighters to Taiwan. China, in retaliation, closed the French consulate in Guangzhou and excluded French companies from bidding for major infrastructure projects. In view of the Chinese concerns over weapon sales, according to the communique, the French Government ''has undertaken not to authorise any French firms to participate in the arming of Taiwan''. China reaffirmed that arms sales of any type to Taiwan would harm Chinese sovereignty, security and reunification, and it would firmly oppose them. The French Government has reaffirmed its recognition of Beijing as the sole legitimate government of China, and Taiwan as an integral part of Chinese territory, the communique said. The Xinhua statement said both sides have agreed to restore their traditional friendly relations and co-operation. It said the two sides wish to intensify their political consultations, hold regular meetings and develop economic and trade co-operation. More importantly, Beijing said it welcomes participation by French firms to compete in the Chinese market ''on an equal footing''. North Korean leader Kim Il-sung wants to visit China to enlist its help in expanding relations with the West, South Korea's domestic Yonhap news agency reported yesterday. ''North Korea is secretly sounding out the Chinese Government through diplomatic channels on the possibility of Kim's visit,'' Yonhap quoted an unidentifed source as saying in Beijing.