China's new heavy-lift transport aircraft and a successful missile interception test are key steps in expanding the strength and reach of its armed forces, analysts and state media said Monday.

The Y-20, China's biggest home-produced military transport jet to date, took to the skies for its maiden flight on Saturday in the northwest of the country, just months after Beijing's first aircraft carrier entered service.

Pictures showed the bulky green plane -- an aircraft that will enable China to project military power across vast distances -- soaring into a clear blue sky.

The state-run Global Times hailed the flight of the plane numbered 20001 as a "significant milestone", saying China needed the aircraft to "enhance its global power projection".

It will allow China's military to end its dependence on the Russian-made Il-76, a mainstay of humanitarian and disaster relief around the world, the paper quoted a military expert as saying.

The Y-20 has a maximum payload of 66 tonnes, which it can carry as far as 4,400 kilometres (2,700 miles), the China Daily said, and with 55 tonnes on board it could fly from western China to Cairo.

It is big enough to hold the heaviest tank used by China's army, the paper added, quoting a military expert as saying that "the heavy air freighters will ensure that we are able to safeguard our interests overseas".

"With them, we can transport our people or large equipment to farther destinations," said Liang Fang, professor of strategy at the PLA (People's Liberation Army) National Defense University.

The test flight was a "big step" for China's air force, said Andrei Chang, editor-in-chief of the Canadian-based Kanwa Defense Review, but added that the Y-20 was technologically inferior to other military transport planes.

True figures for the Y-20's maximum load and flying range were likely to be lower than those cited in state media, he added, due to the plane's reliance on a "very old" Russian-designed engine.

"(The engine's) oil consumption is very bad, it wastes a lot of fuel," he said, pointing out that because of noise some developed countries have banned aircraft using it from landing, threatening its potential appearance at European air shows.

The Y-20 was likely to take at least another five years to enter operational service, he added, and its design appeared to incorporate features from the world's most advanced military cargo plane, the US-made Boeing C-17 Globemaster.

But Chang said that the C-17 was a "much better plane", one of the reasons being that it apparently uses a much higher proportion of lightweight composite materials, which China struggles to produce.

The US Air Force says on its website that it has more than 200 C-17s in its inventory.

Also at the weekend, China announced a successful land-based missile interception test following an earlier one in 2010, the official news agency Xinhua reported.

"The test has reached the preset goal," it quoted a defence ministry official as saying, without giving detailed information. "The test is defensive in nature and targets no other country."

In a commentary Monday on the launch, Xinhua said the test, together with "a string of other military equipment progress" including the aircraft carrier and the heavy-lift plane, demonstrated China's "fast-growing ability to defend its own national security and deter any possible threats".

But it added that the advances were purely defensive, denying any "ill-grounded 'China threat theory'."

China more than doubled its publicly declared military spending from 2006 to 2012, roughly in line with economic growth, but rattling its neighbours in Asia. It insists its army expenditure is not aimed at any other country.

China is currently locked in a bitter dispute over the sovereignty of the Tokyo-controlled Senkaku islands, which Beijing calls the Diaoyus, in the East China Sea.