Economic and fiscal policy minister Akira Amari, a key policymaker and trade negotiator of the Cabinet, confessed Thursday that he has early-stage tongue cancer but vowed to stay at his post.

A government source said the cancer is in a very early stage and can be easily cured with surgery.

Amari told a news conference that his doctor said he will be able to return to his duties in three to four weeks.

He also said he had at one time expressed his intention to Prime Minister Shinzo Abe to resign from the Cabinet, but he changed mind after Abe begged him to stay.

Amari is one of Abe’s closest allies and a key promoter of the prime minister’s “Abenomics” economic and financial policies. In September, Bloomberg chose him as one of the most influential 50 people in the world.

Amari is also the minister in charge of Japan’s participation in the Trans-Pacific Partnership free trade negotiations. He had planned to go to Singapore for TPP talks starting Saturday, but his vice minister, Yasutoshi Nishimura, will go in place of Amari.

Amari entered a hospital early this week, raising speculation about his health.