BERLIN, Jan 5 (Reuters) - The Omicron coronavirus variant causes a quarter of all new COVID-19 cases across Germany and is likely to become the dominant variant across the country in a matter of days, a health ministry spokesperson said on Wednesday.

Omicron is already the most common variant in some German federal states, especially in the north of the country, a health ministry spokesperson told a regular news conference.

"In this respect we must actually assume that in a short time, in a matter of days, it will also become the dominant variant across the whole country," the spokesperson said. (Reporting by Zuzanna Szymanska, Editing by Miranda Murray)