TOKYO - Japanese Prime Minister Shinzo Abe, in his first policy speech to Parliament since he was returned to power, said he intends to move forward on revising the nation's 70-year-old Constitution.

While Mr Abe has previously stressed that he will not ditch Japan's pacifist stance, critics fear that his intended change to the war-renouncing Article 9 will be the start of a slippery slope towards a remilitarised country.

"I'm convinced our discussions on constitutional revision can go forward in our collective wisdom as we strive to find answers to the difficult issues confronting Japan," he said on Friday (Nov 17) at the tail end of his 20-minute speech in a direct address to opposition lawmakers - who broke their stony silence with a round of heckling.

"This is only possible as we implement and execute policies. Let's face the difficult challenges that Japan is facing in a straightforward way together, and work towards opening up the country's future," he said.

Mr Abe's ruling Liberal Democratic Party (LDP) and its coalition partner Komeito control a "two-third" supermajority in Parliament's lower and upper chambers - the level of support required to move any revision to the Constitution towards a public referendum. The proposed changes will require a majority vote by Japanese citizens.

He also said, without giving a concrete timeline, that Japan would try to see that the Comprehensive Progressive Agreement for the Trans-Pacific Partnership (CPTPP) was brought into effect early. This was agreed in principle last week by the 11 countries excluding the United States, whose President Donald Trump withdrew from the TPP in one of his first acts in office.

Friday marked Mr Abe's first policy speech to the Parliament since his party was overwhelmingly returned to power at a snap election last month. The Prime Minister, who has been in power since December 2012, was re-elected to the hot seat by lawmakers in a session on Nov 1.

His address to a packed chamber was intermittently met with raucous clapping from ruling coalition lawmakers, as Mr Abe vowed breakthroughs in the North Korea impasse and in tackling his nation's declining birthrate.

He also discussed moving Japan, whose growth has been stymied by corporate inefficiency and a chronic lack of women representation in the workplace, towards a "productivity and human resource development revolution".

On North Korea, which intelligence officials say has been making technological progress, Mr Abe said: "It is not an exaggeration to say that the security environment surrounding Japan is the most severe after World War II."

He reiterated that Japan will gear up preparations for "every possible siutation" if provocations escalate, under the framework of a "strong Japan-US alliance".

His remarks came days after high-level summit meetings in Vietnam and Philippines, where together with US President Donald Trump, he impressed upon global leaders the need for coordinated action against North Korea.

The last provocative act by North Korea was on Sept 15, when it fired a second missile over Hokkaido, although the war of words since then has not let up.

Mr Abe added on Friday, without giving any concrete details, that Japan will "strengthen its defence capability including the missile defence system".

Mr Trump said in a sales pitch in Tokyo last week that Japan is buying a lot more US military equipment that will create "a lot of safety" for the country.

While Tokyo walked back on this and said the purchase of any new defence gear will follow a Medium Term Defence Program that expires in March 2019, Mr Abe's remarks on Friday could imply more massive acquisitions under the next plan, to be drawn up next year.

Mr Abe also said that early childhood education will be made free of charge for all those aged between three and five by 2020, so as to spark a "human resource development revolution".

It is his goal, through such support in child-rearing, to create a "social security system for all generations". While much of this will be paid for through additional tax revenue, after consumption tax is raised to 10 per cent from 8 per cent in October 2019, he said that Japan will continue to keep an eye on its fiscal debt burden.

He also discussed huge investments in the fields of robotics, Internet of Things, and innovation in the three years until 2020, so as to drive a "productivity revolution".

Mr Abe said on Friday: "Japanese citizens have indicated their desire for stable politics. We will work on these policy pledges one by one and deliver results. Let us all have constructive debates, while advancing policies for the people together."