Nathaniel Gleicher said in a thread on Twitter that Facebook made the changes based on feedback from activists, journalists, and civil society groups.
He also said the platform, which is seeing a proliferation of new Taliban accounts despite a ban on the group, had provided a tool to help Afghans quickly lock their accounts if they feared being targeted.
On Facebook-owned Instagram, Gleicher said, the company is adding pop-up alerts in Afghanistan that include steps for protecting accounts. He also urged people with friends and family in Afghanistan to tighten their own visibility settings.
Mr Gleicher also added that Facebook was "working closely with our counterparts in industry, civil society and government to provide whatever support we can to help protect people".
Meanwhile, Twitter said in a statement this week that its "top priority is keeping people safe, and we remain vigilant".
The social network’s strict bans on the Taliban have pushed many of its most influential voices and officials to Twitter. Still, the platform has struggled to keep out all accounts
Professional networking site LinkedIn has also temporarily hidden the connections of its users in Afghanistan so other users cannot see them, a company spokesman said.
Human rights groups have voiced concern that the Taliban could use social media platforms to track citizens’ digital histories and social connections.