The appropriateness of using this expression is not altogether dependent on any knowledge or expectation on the part of discourse participants that they are going to see each other later. These are Maori greetings. It was thrilling to hear them conversing together spontaneously in their language during their visit to the wrong side of the world. This is a formal greeting. There is no copula in Maori.
Stress is on the first vowel of each word.
Vowels with a macron are long. For a more informal greeting see kia ora below. However, most English seem to think that Kia Ora is a brand of orange squash. This is a Hawaiian greeting. These are Yiddish greetings.