Yahoo TV

The UK's new $4.2 billion aircraft carrier is underway on its maiden voyage, an eight-month tour that will cross through the South China Sea.

And in doing so, send a clear signal to Beijing.

Fighter jets took off from the deck of the HMS Queen Elizabeth this week in the Mediterranean, as part of NATO exercises.

Watching the drills was NATO Secretary-General Jens Stoltenberg himself.

"It sends a message of NATO's resolve and our capability and willingness to defend all allies against any threat. And it also sends a message of how NATO allies can operate together."

China claims 90% of the South China Sea, although several regional countries contest the boundaries and the U.S. has regularly sent warships through the area.

Britain was the main battlefield ally of the U.S. in Iraq and Afghanistan and, alongside France, the principal military power in the European Union.

But its 2016 vote to leave the EU raised questions about its global role.

London announced its biggest military spending increase since the Cold War late last year, partly in response to those concerns.

Commodore Steve Moorhouse is the vessel's captain.

"I think again it shows that we're a global navy and wanting to be back out there. We'll be operating with the United States but also regional partners: Singapore, Japan, the Republic of Korea, other ASEAN nations. We'll not only be exercising militarily but also supporting the government's wider objectives in the region. The economies out there are growing, it's an increasingly important part of the world. So hopefully the aim for us is this deployment will be the first of a more persistent presence for the United Kingdom in that region."