I think it is Arctic, but it may be hard to have a definite conclusion from these photos.
Features that fits Arctic
1. The bird seems "long"
2. Primary projection seems long
3. The bill-tip is dark
Features that are not typical Arctic
1. The two wing bars (Arctic usually have 1 thin wing bar)
2. The supercilium (eyebrow) is board, and not sure whether it reach the base of bill (Arctic often has a thin supercilium that do not reach the bill base)
Overall, I think it is Arctic, unless the primary projects is really much shorter than I thought, or there is a clear crown stripe. Possible confusions are Two-barred Greenish Warbler and Eastern Crowned Warbler, or may be even Goodson's Leaf Warbler.
HF Cheung