The US and Russian presidents may swap compliments at their first summit in Helsinki, but they are deeply divided on issues including Syria, Ukraine and alleged Russian election-meddling.

Washington has imposed a series of sanctions against Russia over recent years, some of which Mr Trump himself reluctantly signed off on after taking office in 2017.

Here is a summary of the sticking points between the two powers:

Russian 'meddling'

Since the start of Mr Trump's presidency, relations have been tainted by allegations of Russian interference in the 2016 US election and suspicions that the billionaire's campaign team colluded with the Kremlin.

Russia has denied any interference. US Secretary of State Mike Pompeo has insisted that Mr Trump at his meeting with Mr Putin "will make clear that meddling in our elections is completely unacceptable".

Ahead of the summit, 12 Russian military intelligence agents were indicted for hacking Democrats during the election.

War in Ukraine

Along with its Western allies, the US accuses Moscow of providing military support to pro-Russian separatists fighting government forces in eastern Ukraine. Russia denies this.

Washington long resisted providing lethal weapons to Ukraine, fearing this could exacerbate the conflict, but in March the US approved a deal to sell anti-tank missiles to Kiev, angering Russia.

Mr Trump has made evasive comments on whether Washington might recognise Russia's annexation of Crimea from Ukraine.

Syria attacks

Air strikes on Syria by the US and its allies in April 2017 and April 2018 in response to alleged chemical attacks by President Bashar al-Assad's forces have infuriated Russia.

In February, Moscow said a number of Russian civilians were killed by US-led coalition bombing. These were reportedly mercenaries fighting alongside pro-regime forces.

North Korea

Russia reacted positively to a June 12 meeting between Mr Trump and North Korean leader Kim Jong-un.

They signed a joint declaration but did not achieve any concrete breakthroughs on Pyongyang's nuclear activities.