BEIJING - When discussing the normalization of Sino-US relations, senior diplomat Ding Yuanhong said that "the strategic views" of both countries' leaders are very important, even for future Sino-US relations.

Ding, 81, was the director of the department of American affairs with the Foreign Ministry when former US president Richard Nixon visited China 40 years ago.

In February 1972, Nixon traveled to Beijing, Hangzhou and Shanghai, and the two governments issued the Shanghai Communiqu, which has remained the basis of Sino-US ties.

"Before Nixon came, he was known as an anti-communist and right-wing figure," Ding told China Daily after a group interview with diplomats who witnessed the normalization of Sino-US relations.

Ding said Nixon's visit "astonished the whole world".

At that time, bilateral relations were frozen as the US viewed China as a foe, placed an embargo on trading and denied China's sovereignty of Taiwan.

"The visit showed Nixon's guts and wisdom," Ding said.

Ding said it was also not easy for Chinese leaders to accept Nixon's visit, which took place during the "cultural revolution".

"Chairman Mao Zedong and Premier Zhou Enlai took the step forward out of the overall strategic consideration and China's diplomatic situation in the world," Ding said.

In the late 1960s, both countries began sending signals that relations were improving, especially after Sino-Soviet border clashes in 1969 and US' involvement in the Vietnam War.

On Oct 1, 1970, after reaching out to each other through their diplomats in Poland, a large picture of Mao's meeting with US journalist Edgar Snow appeared on the front page of People's Daily.

"Actually it was a signal sent to the US, but the US didn't realize it immediately," Ding said.

Shortly after Mao learned Nixon had told Time magazine that he wanted to visit China, Mao met Snow again in December and told him that he welcomed Nixon to visit China either as a "president" or a "tourist", Ding recalled.