He spoke yesterday at a vigil in Invercargill, where hundreds of people had gathered at Wachner Pl to show their support for Christchurch.
Sir Tim said this was a moment for the country to stand together as a nation.
"The tragic events of Friday have left every New Zealander with a mix of emotions ... hurt, fear, shock and disbelief that this could occur in our peaceful nation.''
Imam Reza Abdul Jabbar said "the terrorists'' would not succeed in instilling fear and division in the country.
His 16-year-old daughter, Aisha Abdul-Jabbar, also spoke to the crowd.
"We could not believe this happened,'' she said.
Mckenzie Dawson organised the vigil via her Facebook page and a minute's silence was observed during the ceremony.
Cr Toni Biddle sang Amazing Grace and also invited everyone attending to sing the national anthem.
Imam Abdul Jabbar told the Otago Daily Times he was overwhelmed with the support shown.
"We appreciate this as a community. We know that we can count on our fellow Southlanders ... We thank them, we thank New Zealand and our nation.''