LONDON, Feb.8 (Xinhua) --

He issued a stark warning that Japanese firm's will quit Britain if the outcome of Britain's future relationship with the European Union made it unprofitable for them to stay.

The ambassador addressed waiting media outside 10 Downing Street after May hosted a roundtable meeting with senior representatives of Japanese businesses that are significant investors in Britain.

Japan's interests in Britain include car builders, banks and tech companies.

Tsuruoka said: "If there is no profitability of continuing operation in the UK, not Japanese only, no private company can continue operations. So it is as simple as that. And this is all high stakes that I think all of us need to keep in mind."

He said Japanese companies were enjoying their operations in Britain and wanted to stay in the country, but that the decision, he added, rested on the outcome of the Brexit negotiations.

"The question is whether the arrangements that will be reached between the two sides will allow the Japanese companies, who are willing and in some ways determined to continue to operate in the UK, to make that happen. This is contingent on a number of factors and there is not just one single factor that will be determining the decision," said Tsuruoka.

He said Japanese companies were watching very closely and needed clarity and certainty, predictability.

May was joined at the meeting by Chancellor of the Exchequer Philip Hammond, Business Secretary Greg Clarke and International Trade Secretary Liam Fox.

A spokesperson for Number 10 said later: "The prime minister discussed the role of our modern Industrial Strategy in making the UK an even more attractive destination for Japanese and international investment, as well as the UK-Japan trade and investment relationship."

Discussions covered the opportunities and challenges presented by Britain's exit from the EU.

The Downing Street spokesperson added: "The prime minister set out her vision for an outward looking, global Britain, and the long-term opportunities presented by the modern Industrial Strategy. The Japanese businesses present spoke of their desire to continue trading with, and investing in the UK.

"The Prime Minister reaffirmed the government's commitment to securing a new deep and special partnership with the EU as the UK leaves the EU," said the spokesperson.