Erdogan plans to muster a show of support this weekend in the Turkish heartland, where he has a strong base.
The prime minister told parliament that rallies will be held on behalf of the Justice and Development Party in Kayseri on Friday, in Samsun on Saturday and in Erzurum on Sunday.
U.N. High Commissioner for Human Rights Navi Pillay on Tuesday expressed concern about the tactics used by security forces against demonstrators.
"I am particularly concerned about allegations of excessive use of force by police against peaceful groups of protesters as this may have resulted in serious damage to health," she said in a statement issued from Geneva.
"Reports that tear gas canisters and pepper spray were fired at people from close range, or into closed spaces, and the alleged misuse of rubber bullets, need to be promptly, effectively, credibly and transparently investigated," Pillay said, noting that "the atmosphere is still clearly highly combustible."
And Human Rights Watch said Monday that the Turkish government's response to weekend protests was excessive. "The police assault on a peaceful crowd in Gezi Park and tear gas use in confined spaces showed a dangerous disregard for the well-being -- and indeed the lives -- of protesters and bystanders," said Emma Sinclair-Webb, senior Turkey researcher for the rights group.
"The repeated police violence against people who are dissatisfied with government policies has deeply polarized Turkey. The government urgently needs to change police tactics and issue a clear signal for restraint."
But Erdogan defended the police approach.
"The police forces have passed the democracy test," he said Tuesday, according to the semiofficial Anadolu Agency news service.
He described the use of tear gas on protesters as an "incontestable right of police" and the demonstrations as "an unprincipled, immoderate movement that is based on lies and deception," Anadolu reported.
Trade unions had tried on Monday to put fresh pressure on Erdogan by mounting a nationwide strike. But a crowd that marched on Taksim Square dispersed when faced with riot squads backed by water cannon.
'There is a level of desperation'
While the protests are unlikely to threaten the rule of Erdogan, who is credited with overseeing a decade of economic growth, they are raising questions about what critics say is an increasingly authoritarian style of governing.
Some demonstrators have shifted to protesting in their local neighborhoods in the city, putting up barricades. Meanwhile, the atmosphere in confrontations between police and protesters is turning uglier.
"Now it feels like there is a level of desperation," said Clare Murray, who was vacationing in Istanbul from New York for the past week. "The police seem more comfortable with using aggression."
Since Saturday night, 116 people have been detained during protests in Ankara and 242 people have been detained in Istanbul demonstrations, said Huseyin Aslan, general secretary of the Progressive Lawyers Association.
Erdogan has accused outsiders of taking advantage of the protests over the park. On Sunday, thousands of his supporters gathered at a rally a few miles from Taksim Square, waving flags and singing songs at a rally that was widely viewed as a re-election rally for the prime minister.