Washington, United States: Shinzo Abe is expected to become the first Japanese prime minister in history to address a joint session of the US Congress, crowning an April visit focused on deepening trade and military ties.

Abe hopes to make the speech during a trip to the United States at the end of next month, around Japan's ‘Golden Week’ holiday, diplomatic and legislative sources told AFP.

The invitation has been sent, according to a congressional aide and official announcement is expected soon.

Few Japanese politicians have ever addressed Congress and none have done so in a coveted joint meeting or session of the Senate and House of Representatives. 

On 8 December 1941 a joint session led to a declaration of war against Japan following the attack on Pearl Harbor.

There had been some opposition to the invitation because of Abe's stance on World War II ‘comfort women.’

Mainstream historians say up to 200,000 women, mainly from Korea but also from China, Indonesia and other Asian nations, were forced into sexual slavery during World War II.

Abe is accused of embracing a ‘revisionist’ account of events.

South Korean President Park Geun-Hye in particular has called for him to do more to address the issue.

Japan says it has already apologised, offered financial compensation and psychological help to victims.

The speech is expected to echo some of the themes from Abe's July speech to the Australian parliament.

Speaking in English, he expressed humility about the ‘evils and horrors’ of Japan's history.

Trade and military ties

Abe's visit is also likely to push forward talks on the Trans-Pacific Partnership -- a trade deal bringing together a dozen nations including Australia, the United States, Japan, Mexico and Vietnam.

Negotiators hope that by the time Abe arrives President Barack Obama will have won backing from Congress to close negotiations on the deal.

Obama is seeking so-called fast-track authority that would allow the White House to agree the deal and submit it in its entirety to Congress to ratify, without the power to make amendments.

The US government estimates the country ships almost two billion dollars' worth of goods to the Trans-Pacific countries every day.

But Obama faces some opposition in Congress, chiefly from within his own Democratic party, and from trade unions who worry about labour standards in the signatory countries and that jobs may be shipped overseas.

If Obama gets the authority from Congress, diplomats believe a comprehensive trade deal could be signed quickly after.

Abe's visit is also expected to develop closer military ties between the two countries.

Efforts are already underway to update ‘defence cooperation guidelines’ that govern military relations.

The revisions may allow Japan to come to the aid of US ships that are attacked in the Western Pacific or the South China Sea.

The region is rich in oil and the subject of major territorial disputes between Russia, China, Japan, South Korea, Vietnam and others.

It has also seen a considerable military build-up in recent years.

The change in the guidelines comes after Japan revised the way it interprets Article Nine of its constitution - which outlaws Japan going to war.

The new interpretation would allow for self-defence.