Matt Baggott's warning came just hours before fresh disturbances erupted in Belfast last night, with police coming under attack for a fourth night in a row.
A mob hurled steel barriers, bricks, fireworks and bottles at officers patrolling Castlereagh Street in the east of the city.
A protest in the area earlier in the day had dispersed, before factions broke away and launched an onslaught on police lines.
Disorder was also reported on Mountpottinger Road and Beersbridge Road, where a car was set ablaze. But PSNI chief constable Mr Baggott has signalled his rank-and-file were fully prepared to deal with the ongoing street disturbances.
"I want to commend the tireless courage of my officers at this very difficult time," he said.
"Fifty two colleagues have now been injured while protecting the community during a series of violent incidents.
"You may be assured there will be sufficient resources in the event of more disorder for however long is necessary."
Mr Baggott said the PSNI will do "everything possible" to maintain law and order and deal firmly with the ugly scenes that have marred Northern Ireland over recent days.
He added: "As you have seen in the last few days we will continue to apprehend and put people before the courts."
So far, 70 people have been arrested in connection with the sporadic rioting over the flying of the union flag on Belfast's City Hall.
Through special sittings of the city's magistrates court, 47 people have already being charged.
On Saturday, frontline officers reported coming under gunfire. A 38-year-old man was arrested on suspicion of attempted murder.
More than 1,000 demonstrators had earlier marched on City Hall, but despite tense scenes and some scuffles the rally passed off without major incident.
As the flag-waving crowds broke up, violence again flared on the Newtownards Road and surrounding areas in the traditionally unionist east of the city.
Around 100 loyalists hurled petrol bombs, fireworks, smoke canisters, bricks and other masonry at officers, the PSNI said. Laser pens were also directed at officers' faces.
Police responded with water cannon and fired three plastic bullets. One officer was injured.
Politicians and church leaders held talks at Rev Mervyn Gibson's Westbourne Presbyterian Church to try and forge a resolution.
Rev Gibson said unionist leaders are seeking meetings with police chiefs over allegations of brutality by some PSNI officers.
"People saw batons being used against some who weren't involved in the rioting," he said.
"There's a genuine feeling that there was a change in tactics, that the gloves were off.
"In these instances, not everybody is a rioter."
Rev Gibson said some community leaders believed there was brutality by some members of the PSNI.
Some described it as an overreaction, while others said they would await the outcome of any evidence, he added.
The meeting was attended by two unionist MLAs, the DUP's Robin Newton, the UUP's Michael Copeland, UUP leader Mike Nesbitt and other unionist councillors for the East Belfast.
It's understood figures close to loyalist paramilitaries also turned up.
Mr Newton said a lack of engagement from protest organisers was making it difficult to see an end to the unrest.
"We have to find a way out of this, but how we do it I don't know," he said.
The British National Party and other far right groups had also been addressing recent rallies, the East Belfast MLA said.
"I think we need a bit of calm and reflection," he added. "We need to get wise heads together."
Mr Copeland said there was no apparent leadership to the demonstrations. "There doesn't seem to any one person, or group of persons, that we can go to," he said.
Naomi Long, Alliance Party MP for East Belfast, who received a death threat over her party's role in the flags controversy, said she has not been invited to the talks.
Terry Spence, chairman of the Police Federation for Northern Ireland, said gunfire against police officers was a worrying development.
"What it quite clearly demonstrates is the fact that paramilitaries have hijacked this flags protest issue and they have turned now their guns on the police," he said.
An attack on the home of an SDLP South Belfast councillor was linked the disturbances, the nationalist party said.
Shots from a high-powered ball bearing gun were fired at Claire Hanna's front windows and door seven times.
Cllr Hanna, her husband and baby daughter, were not at home at the time.
SDLP leader and South Belfast MP, Alasdair McDonnell, said unionist leaders and protest organisers needed to take full responsibility for the attack.
Loyalist violence on Friday night saw 18 people arrested and nine police officers injured. More than 30 petrol bombs, along with fireworks, ball bearings and masonry were hurled at officers.
Up to 300 people were involved in the disturbances.
On Thursday 10 police officers were injured during a demonstration.
Street protests have been going on for more than a month now against the decision to reduce the number of days the Union Flag is flown from Belfast City Hall.
The PSNI said it would be seeking further arrests in the coming days in relation to the disorder and have appealed for witnesses.