The Kremlin said on Monday that it did not rule out the possibility of a meeting between Vladimir Putin and Donald Trump if the Russian and U.S. presidents were both in Beijing at the same time in September.

Kremlin spokesman Dmitry Peskov confirmed that Putin would visit China for events to mark the 80th anniversary of the end of World War Two, but said Moscow had not heard if Trump planned to go.

"You know that we are preparing for a trip to Beijing, our president is preparing for this trip... But we have not heard that President Trump is also going there, to Beijing," Peskov said when asked if the two leaders could meet, including possibly in a three-way format with Chinese President Xi Jinping.

"If it so happens that (Trump) is there, then, of course, we cannot rule out that the question of the expediency of holding a meeting will be raised," Peskov told reporters.

The Times newspaper reported last week that China was positioning itself to hold a summit between Trump and Putin.

Putin and Trump have spoken at least six times since Trump returned to the White House in January. The Kremlin has said it is in favor of a face-to-face meeting between them, but this would need careful preparation in order to produce results.

Trump has expressed growing frustration with the Russian leader over a lack of progress towards ending the war in Ukraine, saying earlier this month that "we get a lot of bullshit thrown at us by Putin."

Trump said last week he would impose new sanctions on Russia and buyers of its exports in 50 days unless Moscow agreed to a peace deal. That deadline will expire in early September, coinciding with the war anniversary events in Beijing.