The number of new coronavirus cases has risen in Europe after six weeks of decline, the World Health Organization said on Thursday.

"Last week, new cases of COVID-19 in Europe rose nine percent to just above one million. This brought a promising six-week decline in new cases to an end, with more than half of our region seeing increasing numbers of new infections," WHO Europe's regional director Hans Kluge told a news conference.

"We are seeing a resurgence in central and Eastern Europe. New cases are also on the rise in several western European countries where rates were already high," he said.

"We need to get back to the basics. We need to enlarge" the vaccine portfolio, he said.

WHO's Europe region comprises 53 nations and vaccination drives have begun in 45.

According to an AFP tally based on official numbers, 2.6 percent of the European Union's population have received two doses of Covid-19 vaccines and 5.4 percent have got one dose.