Trade ministers of Japan and Singapore on Wednesday pledged to maintain the high standards of market access and rules of the Trans-Pacific Partnership free trade deal, which China and Taiwan made a bid to join last year, Japan's government said.

In a joint statement, Japanese trade minister Koichi Hagiuda and his Singaporean counterpart Gan Kim Yong confirmed their countries' commitment to "building a free and fair rules-based trading system including through maintaining" the high standards of the deal, according to Japan's Ministry of Economy, Trade and Industry.

Japan and Singapore are part of the 11-member TPP, formally known as the Comprehensive and Progressive Agreement for Trans-Pacific Partnership. Singapore chairs the TPP Commission, the bloc's decision-making body, this year, following Japan's stint in 2021.

The statement was issued after Hagiuda visited the city state and met his counterpart during a six-day tour of Southeast Asian nations also including Indonesia and Thailand through Friday.

Hagiuda and Gan said they aim for the expansion of the TPP to "those able to fully meet, implement and adhere to its high standards," according to the Japanese ministry.

The pact has been attracting attention following official applications for membership by China and Taiwan in September, as well as by the United Kingdom in February.

Japan has welcomed the envisaged accession to the TPP by the United Kingdom and Taiwan, but has taken a cautious position on China due to concerns over Beijing's stance on intellectual property and market-distorting subsidies.

Meanwhile, Singapore was reported to have welcomed China's bid to join the deal following a phone call between Singaporean Prime Minister Lee Hsien Loong and Chinese President Xi Jinping in mid-October.

South Korea also reportedly aims to submit its application to accede to the TPP before President Moon Jae In's term ends in May.

To join the TPP, an applicant needs the approval of all 11 existing members -- Australia, Brunei, Canada, Chile, Japan, Malaysia, Mexico, New Zealand, Peru, Singapore and Vietnam.

Hagiuda and Gan also signed a memorandum of cooperation on reducing carbon emissions, while vowing to deepen their partnership in areas such as digital economy and supply chain resilience, according to the Japanese ministry.