He said many of those killed or injured were originally from Indonesia, or maintain family connections there.
Peters' original purpose for visiting the Indonesian capital of Jakarta was to attend High-Level Dialogue on Indo-Pacific co-operation, hosted by Indonesian Foreign Minister Retno Marsudi.
He leaves for Jakarta tonight.
After his Indonesian visit, Peters said his intention was to travel to Turkey at the request of the Turkish Government, to attend a special ministerial meeting of the Organisation of Islamic Co-operation being held in Istanbul.
"This important event will allow New Zealand to join with our partners in standing against terrorism and speaking up for values such as understanding and religious tolerance.
"We are very clear that the terrorist attack in Christchurch, committed by a person who is not a New Zealander, is utterly contrary to our core beliefs," Peters said.
He will be accompanied by the Ethnic Communities Minister Jenny Salesa.
His overseas trips come after representatives from the Turkish Government spent a couple of days in Christchurch to pay their respects to the victims of the terror attack.
"New Zealand has welcomed the Turkish Government's messages of condolence over the large loss of innocent life," Peters said on Sunday.
The trip to Turkey also comes after Turkish President Recep Tayyip Erdogan used the footage of the gunman's attack in one of his election campaign rallies to highlight Islamophobia in Western countries.
According to Turkish media, Erdogan had also said: "They are testing us from 16,500km away, from New Zealand, with the messages they are giving from there. This is not an individual attack, it is organised."
Peters rebuked the use of that footage and Erdogan's comments about New Zealand, saying he had told Turkey's Foreign Minister that it was unfair and dangerous to blame New Zealand.