Chinese President Xi Jinping headed for Russia Wednesday to mark a new era of friendship and reinforce economic ties that had benefitted from Moscow's isolation from the West.
Due to arrive in the early afternoon, Xi will be received with full honours.
He will have talks in the Kremlin with President Vladimir Putin before attending a formal reception and in the evening he will attend a night out at the Bolshoi theatre.
The visit comes five years after Moscow's annexation of Crimea in 2014 led to a serious rift with its Western partners and subsequent turn toward its neighbour to the east.
From Moscow, Xi will travel to Russia's former imperial capital Saint Petersburg to attend the Economic Forum hosted by Putin on Thursday and Friday.
China and Russia "have strong political mutual trust and support each other firmly on issues concerning each other's core interests and major concerns", Xi said during an interview with Russian media ahead of the visit, according to a transcript released by Beijing's official Xinhua news agency.
Putin's foreign policy aide Yury Ushakov said the visit is "a crucial event for our bilateral relations". The Soviet Union was the first country to recognise Communist-ruled China in 1949, he remarked.
He said Xi and Putin would sign a new declaration on "global partnership and strategic cooperation, which enter a new era".