Japan's Prime Minister Sanae Takaichi is on her way to what she expects will be a very difficult meeting with US leader Donald Trump, days after his calls for allies to help secure the war-stricken Strait of Hormuz went largely unanswered.

Takaichi told parliament hours before her departure that she would do everything to maximise [Japan's] national interest.

The three-day visit to Washington was a chance to talk trade and deepen the US-Japan alliance ahead of Trump's diplomatic trip to China - which has now been postponed because of the war.

But now it is the topic of the war that will likely overshadow the meeting, which is shaping up to be a test of Takaichi's friendship with Trump.

Takaichi had acknowledged the challenges she faced, saying before her departure from Japan on Wednesday that she faced a difficult trip. I want to engage in substantial discussions based on Japan's point of view and our way of thinking, Takaichi told reporters. The top priority is the early de-escalation of the situation.

Earlier this week, in a post on his Truth Social platform, Trump posted a request asking countries to help secure the vital strait, pointing out Japan's and other Asian economies' dependence on fuel from the Middle East. However, after receiving a lukewarm response, Trump retracted his request, saying the US did NOT NEED THE HELP OF ANYONE!

As analysts note, while Takaichi aims to build on the warmth of her first meeting with Trump, recent events complicate her ability to respond effectively, particularly as Trump might demand military support during their discussions. Direct military assistance would be controversial in Japan, a country with a pacifist constitution.

Takaichi's trip also comes amidst her efforts to portray herself as a leader Trump can work with, particularly on trade and economic partnerships, crucial for Japan amid rising inflation and a struggling domestic economy.