UK Prime Minister and Russian President Vladimir Putin spoke in a phone call on Monday ahead of the COP26 summit. 

President Vladimir Putin expressed his regret over not being able to attend the climate summit set to start next week in Glasgow, according to a press release from the prime minister's Downing Street office. This is, according to the press release, due to the coronavirus situation in Russia. 

The Prime Minister hoped Moscow would take more ambitious steps towards curbing carbon emissions and ending deforestation, the office said.

"The prime minister was clear that the UK's current relationship with Russia is not the one we want," the office added, highlighting the fact that there still are difficulties between the two countries.

The Kremlin issued a statement saying the two leaders "expressed a common opinion that despite existing problems, Moscow and London should establish cooperation in a number of areas."

The relations between Russia and the United Kingdom grew tense due to many disputes over the last 15 years, mainly over the poisoning of former spy Alexander Litvinenko with Polonium-210, who died in the UK, in addition to clashing positions on key diplomatic issues, such as Syria and Ukraine.

Although President Putin does not intend to participate in the UN climate summit in Glasgow, Boris Johnson hoped Russia would increase its goal of reaching carbon neutrality by 2060 to 2050.

The climate summit will be attended by over 120 world leaders, and it is the biggest climate summit since the 2015 Paris summit. COP26 will not be attended by President Putin nor Chinese President Xi Xinping, raising concerns over the inability to reach an agreement.