Britain should avoid relying on a monopoly provider of equipment in new 5G mobile networks, but there are no easy answers to concerns about using Chinese supplier Huawei, the chief of Britain's foreign intelligence service said on Friday.

Huawei, the world's biggest producer of telecoms equipment, faces intense scrutiny in the West over its relationship with the Chinese government and U.S.-led allegations that its equipment could be used by Beijing for spying.

No evidence has been produced publicly and the firm has repeatedly denied the allegations, which have led several Western countries to restrict Huawei's access to their markets.

Asked if Britain was seeking to manage risks perceived as being attached to Huawei rather than simply to ban the provider, Alex Younger told reporters in Munich: "I think it is a more complicated issue than 'in or out'."

"What I want is a proper conversation about this because it's not inherently desirable that any piece of significant national infrastructure is provided from a monopoly supplier."

Younger said he had not personally felt any pressure from Britain's 'Five Eyes' intelligence-sharing allies - the United States, Canada, Australia and New Zealand - over using Huawei as a supplier.

"I'm not pretending I have the full answer for this, I am saying that it's important for us to work through all of this stuff," he added.

Britain's BT Group said in December it was removing Huawei equipment from the core of its existing 3G and 4G mobile operations and would not use the Chinese company in central parts of the next network.

Younger, in rare public comments for a chief of the Secret Intelligence Service, or MI6, said he would stress at the Munich Security Conference he is attending this weekend that "Britain's commitment to the security of the European continent is unconditional" despite Brexit.

Britain is due to leave the European Union on March 29.

"Even in the past year, I can think of examples where people's lives have been saved in all of our countries as a result of this cooperation," he said. "Bombs haven't gone off as a result."

AL QAEDA RESURGENT

Britain's security relationship with its European allies was being galvanized by common problems such as dealing with militant fighters and brides returning to Europe after the collapse of Islamic State's "caliphate" in Syria and Iraq.

"We are very concerned about this because all experience tells us that once someone has put themselves in that sort of position they are likely to have acquired the skills and connections that make them potentially very dangerous," he said.

"The reality is that so far, it has been a completely manageable problem," he added. "I can't predict accurately what will happen in future, but it's a very complex environment."

Islamic State, or Daesh, has morphed and is proving "adept at inspiring at attacks rather than directing them," he said.

"Al Qaeda, which has always been in a rivalry, and almost zero sum relationship with Daesh, has, I think, undergone a certain resurgence as a result of the degradation of Daesh," he added. "It is definitely not down and out."

Turning to Russia, Younger said he believed it was "intent on breaking up the links and alliances that exist" between Western states and that he was determined to attach a cost to any such efforts.

Asked whether former Russian spy Sergei Skripal and his daughter Yulia remained under threat after an assassination attempt that British authorities blame on Russia, Younger said:

"I think there is a standing threat from the GRU (military intelligence agency) and other Russian intelligence services and that very little is off limits."