The 16-year-old attacking midfielder, who was named on the Magpies' first-team bench for pre-season fixtures against Atalanta and Athletic Club last month, made his international bow during a 3-0 defeat against Norway on Saturday, coming off the bench at the Sarpsborg Stadion.
The Durham-born teenager, younger brother of under-21s midfielder Jamie, then made his first start for Tom Curtis' side in a 3-0 win against the Faroe Islands on Monday before recording his first goal for his country in a 2-1 win over their Finland counterparts on Wednesday.
Miley, who joined Newcastle's Academy at the age of seven, was one of nine United teenagers to sign a full-time scholarship in July.