Her Majesty the Queen has described the world's first fully integrated chain supplying Liquefied Natural Gas (LNG) as a 'truly ground-breaking achievement.'

The Queen’s comments came at the official inauguration ceremony of the South Hook terminal in Milford Haven this afternoon (Tuesday).

The inauguration was carried out by the Amir of Qatar Sheikh Hamad bin Khalifa Al-Thani.

First to arrive was the Amir accompanied by her Highness Sheikha Mozah bint Nasser Al-Missned, followed by Her Majesty the Queen and the Duke of Edinburgh.

The royal parties, also including the Duke of York, were greeted by local dignitaries including Pembrokeshire County Council chairman Anne Hughes, Stephen Crabb MP, Assembly Member Paul Davies and children from Coastlands primary school waving Welsh and Qatari flags.

The children presented flowers to the Qatar Royal Highness and the Queen.

An audience of more than 300 key figures from the State of Qatar, the UK and the global energy sector witnessed the historic milestone at the largest LNG terminal in Europe, which also marks Qatar's first involvement in the downstream gas industry.

Welsh Assembly First Minister Rhodri Morgan was also among the guests.

The Queen said: "I am delighted to join you in this inauguration.

"This project is a truly ground-breaking achievement."

Secretary of State for Energy and Climate Change Ed Miliband, added: "With our own supplies from the north sea in decline, it's projects like this terminal in Milford Haven that are vital to ensure we have a diverse range of options for importing the gas we need.

"This inauguration heralds the first of many shipments from Qatar, which will help to maintain a diverse and secure gas supply for the UK for years to come.

"The UK will be able to look to Qatar to supply us with up to 20% of our peak gas requirements in the future."

Mohammed Al-Naimi, Director and General Manager of South Hook said: "I am very proud and delighted that His Highness the Amir and Her Majesty the Queen have recognised this tremendous achievement.

"South Hook is truly honoured. This has been a ground-breaking project in terms of size, organisation, financing and technological innovation."