HONG KONG — Hong Kong’s embattled leader refused demands by pro-democracy protesters to resign Thursday, and instead offered talks to defuse a week of massive demonstrations that have grown into the biggest challenge to Beijing’s authority since China took control of the former British colony in 1997.

The Hong Kong Federation of Students said in a statement early Friday that they planned to join the talks with the government, focused specifically on political reforms. They reiterated demands that Chief Executive Leung Chun-ying step down, saying he “had lost his integrity.”

A wider pro-democracy group that had joined the demonstrations, Occupy Central, welcomed the talks and also insisted that Leung quit.

Occupy Central “hopes the talks can provide a turning point in the current political stalemate,” it said in a statement. “However, we reiterate our view that Chief Executive Leung Chun-ying is the one responsible for the stalemate, and that he must step down.”

Leung’s comments came at a news conference held just minutes before the protesters’ midnight deadline for him to quit. “I will not resign,” he said. Standing beside him was the territory’s top civil servant, Chief Secretary Carrie Lam, and he asked her to arrange the talks.

The students had threatened to surround or occupy government buildings if Leung did not step down, and the police had warned of serious consequences if the protesters carried out that threat.