David Cameron has defended his decision to promote British arms sales to Indonesia, arguing the South Asian country has the right to be able to defend itself.

The prime minister landed in Indonesia on Wednesday as part of his tour of South East Asia, which began in Japan and is due to end with a historic vist to Burma on Friday.

Joining Cameron on the trip are representatives of British defence firms, believed to include executives from BAE Systems and AgustaWestland.

Much of the criticism has focused on the previous Indonesian regimes use of British made Hawk jets to crush rebels in Aceh a decade ago.

However, Cameron said there was no problem with providing democratic states with the means to protect themselves.

"We have to be honest and straightforward about the problems in the past," he said. "But both Britain and Indonesia have made significant changes since then.

"Indonesia has transformed itself in the past decade into one of the world's most important democracies, with a free media and elections.

"The military no longer plays a role in politics, but fulfils its proper role defending the country from external attack.

"In Britain we now have what is one of the most rigorous and careful arms licensing systems in the world, to ensure that arms do not fall into the hands of those who might misuse them.

"But at the same time we believe that democratic and responsible countries like Indonesia have a right to defend themselves, and to buy the equipment needed to do so.

"Britain makes some of the best defence equipment in the world and it is right that it is available to Indonesia, under the very same criteria that we apply to all our partners around the world.

"And that is why some of our leading defence companies are with me on this visit."

It is not the first time Cameron has been attacked for using foreign trips to boost arms sales. In 2011 he came under fire for taking representatives from British defence firms with him when he toured the Middle East at the hight of the Arab Spring.

It was also announced today that Airbus had secured a £326m order for from an Indonesian airline.

Garuda is to buy 11 A330 planes, shoring up thousands of jobs in the UK. Some 10,000 jobs in the UK are linked to Airbus.

Apart from the sites near Bristol and Broughton, Rolls-Royce makes engines for the craft, and landing gear is also built in Britain.

Cameron's visit to Indonesia coincided with a Tsunami warning as an earthquake of 8.7 of the richter scale was recorded off the coast.