Ties between Beijing and Tokyo have warmed over the past year, but strains over territorial disputes and attitudes towards wartime history persist.
Xi told a forum in Beijing that "peace and friendly cooperation between China and Japan is the common will of the people, and the general trend of events".
He added that "friendship" between the countries "deserves cherishing and protecting," at the event, attended by Japanese delegates including former economy minister Toshihiro Nikai.
During his Beijing visit, Nikai delivered a personal letter to Xi from Abe, Japan's Kyodo news agency said, without giving further details.
Echoing regular pronouncements from Beijing, Xi also mentioned the 70th anniversary of the Japanese surrender in the second world war, and added that "the facts of history cannot be distorted".
"The efforts of anyone seeking to distort or beautify the facts of Japan's acts of militaristic invasion will not be accepted by the people of China," he added.
China is preparing a massive military parade in September to mark the 70th anniversary, and also creating a public holiday.
China's defence ministry said that its army planes on Thursday for the first time flew over the Miyako Strait, between Japan's Miyako and Okinawa Islands.
