Ahead of Prime Minister Atal Bihari Vajpayee's first meeting with Chinese President Hu Jintao in Europe, China on Tuesday indicated that talks are on with India to resolve the Sikkim issue.
"This is a problem that has existed for a long time," Chinese foreign ministry spokeswoman Zhang Qiyue said.
"China and India would like to conduct useful and meaningful exploration on this issue."
China had objected to Sikkim's merger with the Indian Union in 1975.
Differences over semantics and other issues have delayed the framing of an understanding on Sikkim, which would have sorted out many of the misconceptions that bedevil Sino-Indian relations.
Vajpayee is likely to meet Hu either in St Petersburg in Russia or on the sidelines of the north-south dialogue initiated by France on the sidelines of the G-8 meet on June 1.