HONG KONG — Hong Kong’s government on Thursday canceled talks with student leaders of a pro-democracy protest that has blocked streets in the city for nearly two weeks, with a senior official saying the discussions were unlikely to be constructive.

The talks, which had been scheduled for Friday, will not go ahead because they have been “seriously undermined” by remarks from the student leaders, said the official, Chief Secretary Carrie Lam.

Her announcement came hours after student leaders called for supporters to redouble their efforts to occupy the main protest zone — a highway outside government headquarters that they have dubbed “Umbrella Square.” Umbrellas used to combat police pepper spray and tear gas have become a symbol of the nonviolent movement.

“I truly regret that we will not be able to have a meeting tomorrow which will produce any constructive outcome,” Lam said.

Student leaders had vowed not to retreat even as the number of protesters occupying the main thoroughfare and streets in two busy shopping districts elsewhere in the former British colony has dwindled sharply this week.

Pro-democracy lawmakers, who so far haven’t played much of a role in the protests, said they would join in by blocking all government funding requests in the legislature except for the most urgent.

Protesters have occupied the streets since Sept. 28, when police used tear gas in a failed attempt to disperse tens of thousands of people in front of the government complex.