In cultivating the close relationship that has led to jitters in some Western capitals, Chinese President Xi Jinping and Russian President Vladimir Putin have at times appeared to be attempting to one-up each other with compliments and gifts. If that’s the case, China’s leader will have a tough time matching Mr. Putin’s latest offering.

Forestry officials in northeastern China told the official Xinhua News Agency on Thursday that they were trying to locate an endangered Siberian tiger that had been released into the wild by Mr. Putin earlier this year and evidently stolen its way across the border.

"A Russian expert called to tell us the location of the tiger and expressed the hope that we can protect it," Chen Zhigang, director of the Taipinggou nature reserve in China’s Heilongjiang province, told Xinhua.

Citing Russian media, Xinhua identified the tiger as Kuzya, one of three orphaned Siberian tigers Mr. Putin personally helped release into the Zheludinsky regional zoological reserve in Russia’s eastern Amur region in May.

Siberian tigers, also known as Amur tigers, previously roamed across Russia’s Far East, northeastern China and the Korean peninsula, but by the 1940s, they had been driven to the edge of extinction, according to conservation group WWF. After Russia declared it a protected species, the population stabilized at about 450.

Though not an intentional gift, the tiger represents just the latest in many exchanges between the two presidents, whom analysts say share many characteristics. "I have the impression we always treat each other as friends, with full and open hearts," Mr. Xi told Mr. Putin in Moscow last year, according to an official Kremlin transcript. "We are similar in character."

In 2013, when Mr. Xi visited Moscow, Mr. Putin presented the Chinese leader with a photo of his father, Xi Zhongzhun, taken during a visit to the Soviet Union in 1959. In return, Mr. Xi presented Mr. Putin with an embroidered portrait of the Russian president made in Jiangsu province. “So legendary, so beautiful, so amazing,” Mr. Putin responded, according to Chinese state media.

Mr. Xi could choose to take the arrival of the endangered cat as a good omen, as his signature political campaign since taking power has been an anti-graft drive targeting corrupt officials at every level, including high-level “tigers.”

In any case, this is one gift Mr. Xi isn't likely to receive in person. While they may share many similarities, China’s leader has so far not copied his Russian counterpart’s fondness for displays of manly daring.

-- Josh Chin