The gas leaks from the Nord Stream pipelines will continue until the end of the week, Danish Energy Agency (DEA) Director General Kristoffer Bottzauw said on Wednesday.

"We expect that gas will escape the pipes by the end of the week. There is still a great deal of gas flowing out of the three leaks. It seems that there is a pressure drop in the pipes, and therefore slightly less gas flows out than yesterday, and we expect to see that in the coming days as well," Danish news agency Ritzau quoted Bottzauw as saying.

"Then, initially from the Danish side, we will look into the cause and approach the pipes so that we can conduct a thorough investigation."

Monday saw the occurrence and reporting of three leaks from the Nord Stream 1 and 2 pipelines in international waters – two in the Danish economic zone and one in the Swedish economic zone. Authorities are taking care of the leaks in their respective zones.

Danish Prime Minister Mette Frederiksen said at a press conference on Tuesday that it is the "clear assessment" of the authorities that the three leaks on Nord Stream 1 and 2 were deliberate and not accidental.

Denmark and other nations have already demanded an investigation into the leaks. Danish Defense Minister Morten Bodskov said Wednesday that a closer inspection of the pipelines could take one to two weeks.

EU vows to protect energy network 

The European Union on Wednesday promised a "robust" response to any intentional disruption of its energy infrastructure after saying it suspected sabotage was behind gas leaks discovered this week on subsea pipelines run from Russia to Europe.

As gas spewed out under the Baltic Sea for a third day after first being detected, it remained far from clear who might be responsible for any sabotage.

"Any deliberate disruption of European energy infrastructure is utterly unacceptable and will be met with a robust and united response," the EU foreign policy chief Josep Borrell said without naming a potential perpetrator or suggesting a motive. 

An emergency meeting of the United Nations Security Council (UNSC) concerning acts of sabotage against the Nord Stream 1 and 2 gas pipelines is scheduled for Friday, September 30, Russian Deputy Permanent Representative to the UN Dmitry Polyansky said on Wednesday, as Russia had requested a UNSC session in connection with provocations on the pipelines.

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(With input from agencies)