Donald Trump will soon come face-to-face with the man US intelligence services believe directed an unprecedented plot to meddle in the 2016 presidential election and help the US leader take power, Russian President Vladimir Putin.

It is believed that the war in Syria and the conflict in Ukraine will be the main talking points when Mr Trump meets with Mr Putin later this week at the G20 summit in Germany. But it is uncertain whether Mr Trump will bring up how Russian attackers attempted to interfere in the US election. The Russian President continues to deny any involvement in the cyber attacks.

Mr Trump warmed up his visit to Hamburg by speaking to both German Chancellor Angela Merkel and Italian Prime Minister Paolo Gentiloni over the telephone on Monday. Ms Merkel has made it clear that she is displeased with the US's withdrawal from the Paris climate change agreement, and climate was one of the main topics on the call. She and Mr Trump may also clash over the issue at the summit.

However, it appears that Mr Trump's sideline meeting with Mr Putin will be the main attraction at the summit for many. Mr Trump – whose campaign advisers are facing several investigations into whether they colluded with the Russian government – has a difficult task. If he appears too friendly, critics will leap on the meeting as an example of the President being too soft with Mr Putin and the Kremlin. However, if he is too frosty, Mr Trump could lose the chance to try and repair relations that he has admitted are at a low.