Prime Minister Srettha Thavisin hailed his trip to Japan as a success, saying Japan is Thailand's close friend with a "heart-to-heart partnership" forged among the peoples of both countries.
Mr Srettha made the remarks after attending the Commemorative Summit for the 50th Year of Asean-Japan Friendship and Cooperation in Tokyo.
He said that Asean and Japan have enjoyed more than 50 years of relations as Japan has been a crucial partner to the bloc as well as Thailand's major investor.
He said Asean and Japan discussed investment opportunities, tourism, clean energy and the digital economy.
"Thailand and Japan are heart-to-heart partners as relations between the peoples of the two countries have continued to strengthen," the prime minister said.
"The government will launch a visa-free policy to ease travel for Japanese businesspeople," Mr Srettha added.
"The trip is a great success. Discussions also went smoothly.
"Regarding the visa-free policy, [Japan] asked for it during the Apec Summit in San Francisco last month. Japan is an important business partner," he said.
During the summit in Japan, Mr Srettha also delivered a speech under the theme of "heart-to-heart partners across generations".
He said that this partnership, forged via education and cultural exchanges, had promoted mutual trust and understanding.
"Japan has been Thailand's trusted friend," he said.
In Tokyo, he said he also met Japanese Prime Minister Fumio Kishida for talks on the Organisation for Economic Co-operation and Development, which has more than 30 member countries. Thailand is currently applying to become a member.
Mr Srettha on Sunday also delivered a speech on "Partners for Co-creation of Economy and Society of the Future" at the summit, emphasising the "immense potential" in the power of co-creating wealth and forging cooperation between competitors.
He said Japan is currently the world’s third-largest economy and Asean is expected to be the fourth-largest by 2030.
There is high potential for Asean and Japan to co-create new opportunities for future generations, he said. "Seamless connectivity is the key to unlock our potential and promote shared prosperity. Thailand supports the Asean-Japan Comprehensive Connectivity Initiative to strengthen physical, digital and knowledge connectivity.
"Japan’s almost 3 trillion yen investment in quality infrastructure in Asean is a testament to Japan’s commitment, and Thailand encourages even more investment in the future," Mr Srettha said.
The priority is also to strengthen supply chain resilience and promote more cost-effective transport and logistics, he said. Thailand’s Land Bridge Project represents the country’s vision to enhance regional connectivity, and Thailand welcomes prospective investors to be a part of this project, Mr Srettha said. The government has been promoting this project as part of a longer-term vision to boost the economy.