Russia and China appear to be intent on strengthening their alliance and fostering deeper cooperation in the face of increased political and economic hostility from the U.S.

The bid to strengthen bilateral ties continues this week as Chinese President Xi Jinping is in Russia Wednesday for the start of a three-day state visit and top-level talks with Putin.

Welcoming Xi to the Kremlin on Wednesday, Putin said ties between Russia and China stood at "an unprecedented level." Xi echoed that sentiment by saying that the countries' relations had withstood "trials and tribulations" over the years and were now better than ever.

"We've managed to take our relationship to the highest level in our history," Xi said. "We will continue to improve our ties and we are ready to go hand in hand with you," he told Putin at the leaders' initial meeting that was broadcast online.  

On Wednesday evening, Putin and Xi will attend an event to mark the 70th anniversary of diplomatic relations between the two countries. A number of trade and investment deals are expected to be signed, although a Kremlin spokesperson was unable to give more detail when contacted by CNBC.  Xi will also attend and speak at Russia's annual St. Petersburg International Economic Forum (SPIEF) that starts Thursday.

A new chapter

Ahead of the visit, Xi remarked on the blossoming relationship between the countries and the need to foster stronger ties. "I look forward to charting the course of our future relationship together with President (Vladimir) Putin and to seeing that our comprehensive strategic partnership of coordination will stride into a new era," he told Russia's TASS news agency on Tuesday.

"Our two countries enjoy strong political trust and can always count on each other's firm support on issues concerning our respective core interests and major concerns," he noted.

Xi said the countries now had new opportunities for growth and "we have the confidence and capability to bring our relations to a new era of greater development at a higher level."

Chinese Vice Foreign Minister Zhang Hanhui noted at a press briefing Tuesday that the visit will "be of milestone significance in the development of bilateral relations," and "surely promote greater development ... under the new situation," Xinhua news agency reported.

Strong political trust

The meeting of the two prominent global powers comes as Russia's relations with the U.S. are at a low ebb amid continuing sanctions on the country, and China's relationship with the U.S. is fraught with trade war tensions.