Hong Kong officials and student leaders will hold talks to try to end pro-democracy protests gripping the southern Chinese city for more than three weeks, though chances of success are slim given vast differences between the two sides.

The city's Beijing-backed leader won't be attending Tuesday evening's discussions.

Chief Executive Leung Chun-ying has reaffirmed his position that China's communist leaders won't allow Hong Kong citizens to openly nominate candidates for inaugural elections in 2017 to succeed him.

In comments to some foreign media, he said allowing full democracy in the Asian business hub would give the poor too much of a say.

Leung's comments underline how the protests have been fuelled by discontent among the young over soaring inequality in the former British colony.