Qatar and North Korea high on the G20 agenda for Donald Trump

U.S. President greets German Chancellor Angela Merkel - but all eyes will be on his first ever meeting with Russian counterpart Vladimir Putin

U.S. President Donald Trump meets German Chancellor Angela Merkel on the eve of the G-20 summit in Hamburg

North Korea’s nuclear threat, the Middle East’s Qatar conflict and the Minsk Agreements were high on the agenda when Donald Trump met with Angela Merkel ahead of the G20 summit.

The US President and German Chancellor convened in Hamburg to coordinate on key policy areas ahead of Friday’s international forum with world leaders from 20 different countries.

The two leaders shared, what some have described as, an awkward handshake in front of the world’s media.

However the pair share common priorities, which are expected to guide their approach to the summit’s agenda.

An official statement from the White House reads: “The leaders conferred on a range of shared foreign and security policy priorities, including re-energising implementation of the Minsk Agreements, de-escalating the conflict between Qatar and some of its Gulf and Arab neighbours, and de-nuclearisation of the Korean Peninsula.”

The U.S. President will also meet Russian leader Vladimir Putin for the first time on Friday, in an eagerly awaited encounter at a G20 summit marked by the growing divide between America and its Western allies.

On the eve of a face-off that carries consequences for world crises including the wars in Syria and Ukraine, Trump set the tone on Thursday with a strong attack against Moscow for its "de-stabilising" actions.

The property tycoon and the ex-KGB agent's first meeting promises to be dissected frame by frame, with their handshake and body language including each facial twitch to be scrutinised for any sign of rapprochement or estrangement.

"While Trump pro-wrestling approach is showy, bombastic and impulsive, Putin thrives on judo's discipline and mental toughness, where a core technique is to keep an opponent off-balance and exploit his weakness," noted Derek Chollet from think-tank German Marshall Fund.

"How these contrasting styles of machismo interact... will likely be the defining feature of their relationship moving forward."

The blockbuster bilateral meeting comes on the sidelines of what is expected to be the most fraught G20 summit in years in the German city of Hamburg.

Trump's "America First" and climate sceptic stance are set to test the relationship with longstanding allies, while North Korea adds more volatility to global security.

Scenes outside the heavily guarded conference hall were also stormy, as anti-globalisation protesters fought running battles overnight with police who fired tear gas and used water cannon to disperse extreme-left Black Bloc militants late on Thursday.

Trump had alarmed Western partners wary of a resurgent Moscow with his refrain on the campaign trail pledging to have a "great relationship with Putin and Russia".

But amid accusations that Moscow had a hand in propelling him to the White House, Trump finds himself in a tight spot over his complex relationship with the Russian leader.

In a key speech in Warsaw marking his first stop on his European tour, Trump fired a rare salvo of criticism at Russia.

"We urge Russia to cease its destabilising activities in Ukraine and elsewhere, and its support for hostile regimes - including Syria and Iran - and to instead join the community of responsible nations in our fight against common enemies and in defence of civilisation itself," he told a cheering crowd of 10,000.

He admitted that Moscow "may have" tried to influence the 2016 election that brought him to power, but also suggested others too may have been involved and blames his predecessor Barack Obama for failing to act.

When the pair sit down for their afternoon meeting, they will not be short of crucial issues to discuss, including the wars in Syria and Ukraine, North Korea's nuclear programme and efforts to combat terrorism.

A White House source confirmed to AFP that Trump will only be joined in the meeting by Secretary of State Rex Tillerson and a translator, an extraordinarily small cast list that raised concerns among experts.

"Neither Tillerson or Trump have any experience of foreign policy. That is one reason why they need pros in the room when meeting Putin," said Thomas Wright of the Brookings Institution, who added that Trump was now more likely to appease Putin.

Former US ambassador to Russia Michael McFaul expressed concern that Trump's National Security advisor H.R. McMaster and his team - seen as moderating influences in the White House - were being sidelined.

"Putin likes small meetings. This means WH is letting Kremlin dictate the terms of this meeting. HR, at a minimum, should also be there," he wrote on Twitter.

Ahead of the talks, the US also extended a hand of cooperation to Russia, voicing willingness to work together on establishing "no-fly zones" in Syria as part of a joint effort to stabilise the war-ravaged country.

North Korea's successful test of an intercontinental ballistic missile also casts a dark shadow on the US leader's first G20 summit.

In his first public remarks since the test, Trump said in Warsaw that Pyongyang's military sabre-rattling must bring "consequences" and warned he was considering a "severe" response to its 'very, very bad behaviour".

After repeatedly urging Beijing to ratchet up the economic pressure on North Korea, Trump will hold what promises to be a testy meeting with Chinese President Xi Jinping on the sidelines of the G20.

At a dinner meeting grouping north-east Asian leaders but which excluded Xi, Trump was asked if he had given up on the Chinese leader, but replied: "Never give up."

Beyond the complex diplomatic waltz, the US leader also faces tough talks in the main G20 conference room, where a united front is forming against his stance on climate and "America First".

Trump may have vowed to pull the US out of the 2015 Paris climate protection accord, but G20 host German Chancellor Angela Merkel stressed that "many many other countries want to go on implementing" it.

"We are not going to paper over the differences but rather, we will call discord discord," said Merkel.

According to information released by the White House, Mr Trump’s timetable on Friday is expected to begin with a visit to the G20 Summit Leaders Retreat followed by participation in the official event photograph.

After a working lunch with other world leaders, he is expected to spend the afternoon involved in G20 working sessions and has plans for extended meetings with Mexico’s President Peña Nieto and Russia’s President Vladimir Putin.

The day is expected to draw to a close with a special G20 reception, concert and summit social dinner.