Germany's energy regulator, the Bundesnetzagentur, said yesterday that four months, which began on 8 September, are required to complete certification of the now completed Nord Stream 2 gas pipeline running from Russia along the Baltic Sea floor to Germany.

Once the regulator completes its inspection it will send a draft decision to the European Commission.

The Bundesnetzagentur must ensure that Nord Stream complies with European Union rules that require pipeline owners to be separate from the gas suppliers when it reaches and crosses German waters and territory.

German Chancellor Angela Merkel tried to play down fears over the pipeline on a farewell visit to Poland at the weekend, saying she had made clear to Moscow that Ukraine needs to remain a transit country for Russian gas beyond the expiry of a five-year deal in 2024.

The United States shares this view and has long encouraged the shipment of Russian gas through the Ukraine and into Europe.