Katy Perry proved her romance with Justin Trudeau was going strong on Thursday when the couple met up with the former Japanese prime minister and his wife. 

The singer, 41, is currently in Tokyo while she continues her world tour and is being supported by her partner and former Canadian prime minister Justin, 53. 

As their relationship goes from strength-to-strength, the duo tied in Katy's performances with the politician's formal meetings. 

Sharing an update to his Instagram, former Japanese prime minister Fumio Kishida and his wife Yuko, joined Katy and Justin for a photo by the Christmas tree. 

He wrote: 'Former Canadian Prime Minister Trudeau came to Japan with his partner Katy Perry and had lunch with us. 

'During my time as Prime Minister, I met Prime Ministers many times, and when I visited Canada, we worked together to strengthen bilateral relations, including formulating the "Nikka Action Plan". 

Fumio added: 'I am glad that we are continuing this friendship.' 

Katy and Justin were spotted strolling through Asakusa, one of Tokyo's most historic and tourist-loved districts, earlier in the day. 

They later slipped into Asakusa Sumo Stable ANNEX, a restaurant known for its live sumo wrestling matches performed inside an actual ring. 

The pair reportedly enjoyed traditional Japanese dishes while watching the athletes in action.

Their trip marks the latest international outing for the duo, who first sparked dating rumors in July following Perry's split from ex-fiancé Orlando Bloom, 48. 

After weeks of speculation, they made their official debut as a couple in September in Paris, stepping out hand-in-hand during a romantic evening in the French capital.

A source previously told People that Perry and Trudeau have been 'making plans for the holidays' and that the pop star is navigating a whirlwind schedule as she prepares to wrap up her Lifetimes Tour.

'Without exaggeration, this year has been a whirlwind for her. She hasn't even had time to really think about her life after the tour,' the insider shared.

Though her romance with Trudeau has been an exciting new chapter, the source emphasized that Perry remains focused on her five-year-old daughter Daisy Dove, whom she shares with Bloom.

'She's a single mom now and a lot of that is going to come into focus next year,' they added.

The insider also revealed that Perry is 'excited' by Trudeau, noting she is 'having a lot of fun' despite being surprised by how quickly she connected with someone new after the end of her long-term relationship with Bloom.

'Justin keeps making a big effort to see her and she's excited about it. [She has] a lot of fun with him. It's exactly what she needs right now,' the source said.

On Trudeau's side, the relationship appears to have brought a new sense of ease. 

'He is a much happier person now. Stresses are greatly diminished. And he is intrigued with Katy. They have fun together, laugh a lot, talk about everything,' the source added.