MOSCOW (REUTERS) - Russian President Vladimir Putin and British Prime Minister Theresa May spoke by phone on Tuesday (Aug 9) and agreed to meet "in the near future" to try to improve poor relations between Moscow and London, the Kremlin said in a statement.

Both leaders are due to attend a Group of 20 (G-20) summit in China early next month, giving them an opportunity to meet for the first time since May became prime minister in July.

Relations between Russia and Britain are strained by differences over Ukraine and Syria as well as by what London says is a sharp increase in flights by long-range Russian bombers near British air space.

The Kremlin said Putin and May had agreed to try to work to ensure that the two countries' intelligence services communicated with one another properly and to improve air safety, a reference to Russian military flights.

Both leaders had expressed dissatisfaction about the current state of Russian-British relations, the Kremlin said, adding that the phone call had taken place at Britain's initiative.

A spokeswoman for May said both leaders had agreed that British and Russian citizens faced common threats from terrorism, and that cooperation on aviation security was a vital part of the international counter-terrorism effort.

"The Prime Minister noted the importance of the relationship between the UK and Russia, and expressed the hope that, despite differences on certain issues, they could communicate in an open and honest way about the issues that mattered most to them," the spokeswoman said in a statement.

"They looked forward to seeing each other at the G-20 summit in China next month."