waved flags, carried placards saying 'Yes We Can - Stop TTIP!'

President Barack Obama and German Chancellor Angela Merkel made a joint pitch Sunday for deeper transatlantic trade in the face of mounting opposition.

After talks in the northern town of Hannover where tens of thousands marched on Saturday against the planned deal, Obama said the world's largest trade pact could be finalised by the end of the year.

'Angela and I agree that the United States and the European Union need to keep moving forward with the Transatlantic Trade and Investment Partnership negotiations,' Obama said.

The Trans-Atlantic Trade And Investment Partnership (TTIP) has become a tough sell, particularly in Germany.

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President Obama and his political chum Angela Merkel smile as they promote a new US-Europe trade deal

The pair looked to be enjoying each other's company during what is likely Obama's last visit as president

Obama praised Merkel for 'being on the right side of history' by letting migrants settle in Germany

President Barack Obama and Chancellor Angela Merkel embrace as he arrives at the Herrenhausen Palace on Sunday

The pair had a meeting to the proposed US-Europe trade deal which has drawn ire in Germany

Obama also said they discussed tackling ISIS and he will praise Merkel's handling of the migrant crisis

Together, Obama and Merkel launched the world's largest trade fair in Hannover on Sunday

Obama waves at the crowds a day after thousands of people took to the streets to protest his visit

Touch down: President Barack Obama lands at the airport in Hannover, Germany, on Sunday morning

Obama touched down in the city on Sunday morning after a day of promoting the treaty in London

Thousands of demonstrators gathered in Germany to protest a planned free trade agreement between the U.S. and the EU, a day before President Barack Obama arrived

Obama touched down in Hannover on Sunday morning after a day of promoting the treaty in London.

He then opened the world's largest industrial trade fair in Hannover with German Chancellor Angela Merkel, before they had a meeting to discuss TTIP and other issues, including efforts to counter the Islamic State group.

The key factor behind his final stop in Germany as US president was the TTIP.

In a joint press conference after their discussion, Obama and Merkel insisted the trade deal is necessary. Obama also praised Merkel as being 'on the right side of history' by letting migrants come to Germany.

On the trade deal, he said: 'I don't anticipate that we will be able to have completed ratification of a deal by the end of the year, but I do anticipate that we can have completed the agreement.'

Both sides hope the pact will provide a shot in the arm to Western economies that are still struggling to erode the devastating effects of the global financial crisis.

'As you see other markets like China beginning to develop and Asia beginning to develop and Africa growing fast, we have to make sure our businesses can compete.'

Merkel echoed that sentiment, saying the deal was 'extremely helpful to allow our economy in Europe to grow'.

'It is good for the German economy, it is good for the European economy,' she said.

But Obama acknowledged there was popular opposition.

'People are unsettled by globalisation,' he said. 'People visibly see a plant moving and jobs lost and the narrative develops that this is weakening rather than strengthening the position of ordinary people and ordinary workers.'

'The benefits often times are diffused.'

Ahead of the meeting there was a sign of the significant hurdles that remain.

Merkel's Economy Minister Sigmar Gabriel warned the deal 'will fail' if the United States refused to make concessions in 'buy American' clauses.

The streets of Hannover were crawling with activists who bitterly oppose the Trans-Atlantic Trade and Investment Partnership, or TTIP

A man on stilts and dressed like the Statue of Liberty walks in front of balloons forming the slogan Stop TTIP during the protest

Thousands of people took to the streets in protest in Hannover on Saturday, the day before Obama arrived.

Some carried placards that said 'Yes We Can - Stop TTIP!' It was a riff on Obama's 2008 presidential campaign slogan.

Organizers claimed that 90,000 people attended the demonstration in Hannover but police estimate the count was more like 30,000.

In November, more than 100,000 people in Berlin protested against the proposed pact.

Proponents say the deal would boost business at a time of global economic uncertainty. Critics fear the erosion of consumer protections and environmental standards.

Negotiators in Washington and Europe are trying to finalize key parts of the deal before the end of the year, after which Obama's successor and election campaigns in major European countries could further complicate the already difficult negotiations.

The discussions, due to resume on Monday in New York, have come under criticism for the secretive manner in which they've been conducted.

National lawmakers are only allowed to view draft documents in special reading rooms and are forbidden from talking about the documents with experts, the media or their constituents.

Proposals to create dispute settlement tribunals have also stoked fears.

EU trade chief Cecilia Malmstrom envisages special investment courts that would rule in disputes between governments and companies that feel they face undue legal hurdles to their business.

Critics say such courts could place the interests of corporations above those of democratically elected governments, citing a recent case where tobacco giant Philip Morris sued Uruguay over a law requiring graphic warnings on cigarette packages.

Alfred de Zayas, an American law professor and U.N. human rights expert, argues that such courts are unnecessary in countries that abide by the rule of law, such as the United States or the EU's 28 nations.

Backers of the special courts say they would prevent cases from being heard by American jurors who don't understand the complexities of international trade law, and ensure that U.S. companies don't face discrimination in European countries with high rates of corruption.

Juergen Hardt, a German lawmaker and the government's coordinator for trans-Atlantic cooperation, believes some of those leading the fight against TTIP 'have other motivations' beyond trade.

'They also want to incite anti-American feelings,' he said.

Demonstrators waved flags and carried placards with slogans such as 'TTIP? Nein Danke (no thanks)!'

An activist of the environment organization Greenpeace with a banner reading ' Yes we can stop TTIP!' hung from a building crane to show off his poster

The streets of Hannover were crawling with activists who worry that TTIP is a deal favouring only big business

The EU's executive branch is trying to promote the benefits of a deal.

On its website, it suggests that TTIP will boost demand for European delicacies like cheese, hams, wine, olive oil, spirits, and chocolate.

'High tariffs at U.S. customs — up to 30 percent — make some of these hard for Americans to afford — and difficult for European farmers and firms to export,' it says.

TTIP's backers hope images of Obama in Europe — where his popularity remains high — will counter those of tens of thousands protesting the deal.

In her weekly video message Saturday, Chancellor Angela Merkel said everything has been done to improve the transparency of the negotiations — within reason.

And she stated anew that European standards won't be eroded.

'We are not falling behind our standards, but securing those we have in Europe today on the environment and consumer protection,' she said.

Yet time may be running out for a deal. A spokesman for Germany's Economy Ministry said that no draft proposals have been exchanged about numerous areas of negotiation.

The two sides are also divided about the issue of tariff reductions and the opening up of the markets for services and procurement.

'In order to achieve negotiating success this year, it will be crucial to make significant progress by the summer on technical questions, so that the final negotiations are restricted to a few, politically sensitive areas,' said Andreas Audretsch, the ministry spokesman.

Obama said it was important to conclude negotiations even though Congress is unlikely to ratify the deal before he leaves office.

Opponents of a proposed transatlantic trade deal (TTIP) hold a banner reading 'Don't give TTIP any chance. Stop TTIP, CETA, TISA' during a prostest rally on the eve of U.S. President Barack Obama's visit

Protestors demonstrate against the Trans-Atlantic Trade and Investment Partnership (TTIP) free trade agreement

Officials in Washington and Brussels are trying to clinch key parts of the deal before the end of the year

The discussions, due to resume on Monday in New York, have come under criticism for the secretive manner in which they've been conducted

Juergen Hardt, a German lawmaker, said the protesters 'also want to incite anti-American feelings'

Protesters carried placards and waved flags with slogans such as 'Yes We Can - Stop TTIP!'

A man holds a United States flag with the slogan 'For America Against TTIP' during the protests in Hannover

'But if we have that deal, then the next president can pick that up rapidly and get that done,' he told the BBC in an interview broadcast Sunday.

In London on Saturday, he argued for the pact while acknowledging the tough work needed to complete it.

Despite 'enormous amounts of trade' between the U.S. and Europe, 'there's still barriers that exist that prevent businesses and individuals that are providing services to each other to be able to be able to do so seamlessly,' he said.

The pact will bring millions of jobs and billions of dollars in benefits to both sides of the Atlantic, Obama said.

Negotiating trade deals 'is tough,' Obama said, because each country fights for its own interests.

'The main thing between the United States and Europe is trying to just break down some of the regulatory differences that make it difficult to do business back and forth,' he said.

Critics worry that it would erode consumer protection and environmental standards.

Merkel is the world leader with whom Obama has worked throughout his two terms, in good and bad times, and he planned to use the visit to show political solidarity.

He praised her politics in the Sunday press conference.

On Syria, Obama defended his decision not to impose a safe zone that could help stem flows of migrants and refugees into Europe that have hurt Merkel politically.

A protester holds a placard with pictures of German Chancellor Angela Merkel and U.S. President Barack Obama

'Sadly, it is very difficult to see how it would operate short of us essentially being willing to militarily take over a big chunk of that country.'

But he rushed to Merkel's defence over the refugee crisis, saying she was on 'the right side of history'.

Obama's trip follows stops in Saudi Arabia and Britain, where Obama plunged headlong into the debate over membership of the European Union.

Obama pitched in on the side of Prime Minister David Cameron, arguing that Britain would be lose influence and trade opportunities if citizens vote to leave the EU in a June referendum.

During his seven years in the Oval Office, the Democrat US president and the conservative German chancellor have grown closer and Obama sees her, among European leaders at least, as first among equals.

Aides describe a meeting of minds, two leaders who take a cerebral and analytical approach to politics.

'I have valued chancellor Merkel's thinking and perspective on a whole range of global issues throughout my presidency,' Obama said.

'You have been a trusted partner throughout my entire presidency, longer than any world leader, and I value your judgement.'

Merkel echoed his sentiment at their joint press conference.

'What you see is friendly, close, trusting cooperation that I am very pleased with, also because it helps solve international problems.'

The pair will have dinner later Sunday, and Obama will wrap up his visit Monday with a keynote speech designed to frame his vision of transatlantic relations and a meeting with Merkel and the leaders of Britain, France and Italy.

Despite the diplomatic niceties, the relationship between Obama and Merkel has had its rocky moments.

Merkel has backed austerity as the remedy to European sovereign debt crises, while Obama came down firmly in favour of short-term spending to buy time and a way out of the economic downturn.

US-German relations hit a low when it emerged that the US government had been tapping Merkel's phone.

But officials point to the Ukraine conflict as a turning point that helped both leaders begin to work in tandem.

In her weekly video message Saturday, Chancellor Angela Merkel said everything has been done to improve the transparency of the negotiations