The UK government must seek to maintain its strong position in the North Atlantic Treaty Organisation (Nato) after triggering Brexit talks, Labour's Shadow Defence Secretary Nia Griffith told IBTimes UK on Wednesday (29 March).

"Nato is the defence body for Europe and that's where we will be doing our collaboration. We will be there with our transatlantic partners, with our European partners and we need to keep a very strong presence in Nato and we need to keep our commitment to 2% GDP defence spending per year," she said.

The comments came as the UK's top diplomat to the EU, Sir Tim Barrow, hand-delivered Theresa May's Article 50 notification letter to EU Council chief Donald Tusk. The move started the two-year-long divorce talks between Britain and the EU.

Professor Malcolm Chalmers, the deputy director-general of the Royal United Services Institute (RUSI) think-tank, has raised concerns about the UK's position within Nato's command structure post-Brexit.

The Deputy Supreme Allied Commander (DSACEUR) post is traditionally held by the UK, but it could possibly be transferred to one of the other 27 EU members.

"The role of DSACEUR is central to ensuring the availability of Nato assets to certain EU missions organised under the 'Berlin Plus' arrangements, for example in Bosnia. There may be creative ways to handle this issue," he wrote in January 2017.

"A second DSACEUR position could be recreated (Germany held this position until 1993), or the UK could swap its current position for the important role of Chief of Staff.

"Whatever the outcome, the substantive consequences of such changes are likely to be relatively limited. Even so, the fact that they are already being raised is a clear message that the UK's role and influence within Nato cannot be entirely ring-fenced from the consequences of Brexit."

May, in her Article 50 letter, said she wanted to agree to a "deep and special partnership" between the EU and UK with economic and security cooperation.

"Europe's security is more fragile today than at any time since the end of the Cold War. Weakening our cooperation for the prosperity and protection of our citizens would be a costly mistake," she told Tusk.