June 6 (UPI) -- Chinese President Xi Jinping and Russia's Vladimir Putin stressed close ties in a summit in Moscow that included the gift of two pandas to a Russian zoo on Thursday.
Ahead of his visit to Moscow's zoo, Xi told reporters after a three-hour summit Russia is China's closest friend and ally, Russian news agency Interfax reported.
"Russia is the country I visit most frequently," the Chinese leader said. "Putin is my closest friend and a good colleague."
The Chinese government said the two countries agreed to cooperate in key sectors, including energy, aerospace, and the sciences, state new agency Xinhua reported Thursday.
The two sides agreed to set up a $1 billion China-Russia Science and Technology Innovation Fund and increase investments, including construction under China's One Belt, One Road Initiative, according to reports.
Xi and Putin are promoting strong ties at a time the Trump administration is warning that it could further raise tariffs as China responds with penalties against China-based U.S. companies.
The presentation of the two pandas, Ru Yi and Ding Ding, comes after two years of negotiations. China agreed to lend the pandas to Russia in 2019, the 70th anniversary of diplomatic ties.
Russia has invested about $15 million in building a Chinese section of the zoo that would include an area for the animals. Ru Yi and Ding Ding were flown in from China's Szechuan Province in late April. They will be on loan to Moscow for 15 years.
Putin has publicly expressed gratitude for the pandas, following his summit with Xi.
"I thank President Xi and Chinese colleagues for providing the Moscow zoo with two large pandas," Putin said Thursday. "This is a sign of special respect and trust in Russia."
China has not given pandas to Russia since 1957, the 40th anniversary of the Bolshevik Revolution.