The U.S. government, Congress and academics have a very "solid" consensus that Japan should stop its attempts to gloss over its wartime wrongdoings, namely the issue of sex slavery, the South Korean ambassador to Washington said Thursday.

The remarks by Amb. Ahn Ho-young came amid speculation that Washington appears to be "fatigued" as tension over the shared history between Seoul and Tokyo has been protracted without signs of improvement.

"It is my understanding that the U.S. government, lawmakers, scholars and the press shared a very solid consensus about the issue of the shared history between South Korea and Japan," Ahn told a group of reporters in Seoul.

"The U.S. puts significance on its alliance with Seoul in terms of strategic values ... So I'd like to say that we deserve to have more confidence."

The Seoul-Tokyo ties have plunged to their lowest level in recent years as Japan is reluctant to apologize for its sexual enslavement of Korean women for its troops during World War II.

Historians estimate the number of sex slaves at 200,000 with only 53 South Korean victims still alive.

The U.S. seeks to strengthen trilateral security cooperation between Washington, Seoul and Tokyo in an apparent bid to keep a rising China in check. But experts said the long-stained Seoul-Tokyo ties may hamper Washington's efforts.

Recently, controversy flared up in Seoul as U.S. Undersecretary of State Wendy Sherman last month made remarks seen as taking sides with Japan in a sensitive historical row.

Seemingly targeted at Seoul and Beijing, she said political leaders should not try to exploit nationalist feelings and "earn cheap applause by vilifying a former enemy."

Later, the U.S. sought to calm an upset South Korea, saying that Tokyo's wartime sexual enslavement of women was a terrible violation of human rights.

Ahn rejected such speculation over Washington's exhaustion over the matter, taking U.S. President Barack Obama's remarks about the sex slavery as an example.

During his visit to Seoul in April 2014, Obama called Japan's use of sex slavery a "terrible and egregious violation of human rights."

"If we have too much interest, our excessive anxiety or unduly worries over the history issue could even bring about fatigue that does not exist in the U.S.," Ahn said.

Japan has intensified its moves to whitewash its wartime atrocities since Japanese Prime Minister Shinzo Abe took office in late 2012.

In June, Japan reviewed its previous apology over the sex slaves, known as the Kono Statement, saying that the outcome was a political compromise between the two countries.

A group of Japanese historians demanded U.S. publisher McGraw-Hill revise the description of Japan's sexual enslavement of women during World War II in a textbook, claiming there are grave errors in the textbook.

In early February, a group of American history scholars expressed strong protest against Japan's attempts, saying that no government should have the right to "censor history." (Yonhap)