The European Union and 10 Southeast Asian nations were set to hold talks here on Thursday on deepening relations strained by European concerns over human rights abuses.
Foreign ministers from the 27-country EU and the Association of Southeast Asian Nations (ASEAN) were also expected to discuss moves to create a free trade deal between the blocs.
However, the European Union will stress its opposition to the military junta in ASEAN member Myanmar, which it and the United States accuse of massive human rights abuses and suppression of political dissent.
The gathering in the southern German city marks a milestone as the partners are celebrating the 30th anniversary of the establishment of their relations.
German Foreign Minister Frank-Walter Steinmeier, whose country currently holds the EU presidency, said the EU and ASEAN should look at ways of pooling their resources to tackle pressing issues such as climate change.
"The list of future tasks is long, but one thing is clear -- we will only be able to face them if we work together," Steinmeier said in a speech to open the meeting on Wednesday.
"The era of nation states is over, at least to the extent that none of our countries can solve these problems on its own," he said.
"Together however we have a huge pool of resources at our disposal. Some 500 million people live in the EU today, 560 million in the ASEAN countries. That is over one billion citizens or one sixth of the world's population."
EU External Relations Commissioner Benita Ferrero-Waldner said ahead of the meeting that relations between the two regions were "ready to shift up a gear."
Participants are expected to support a statement calling for closer political ties and combined efforts in areas such as energy, security and protecting the environment.
Although a free trade deal between the EU and ASEAN is not officially on the agenda in Nuremberg, the issue is likely to be raised.
The EU executive, the European Commission, expects to receive a negotiating mandate from member states for a free trade agreement with ASEAN in the next few months.
EU efforts to broker a deal were given fresh impetus when ASEAN nations agreed at a summit in the Philippines in January to create a single market of their members by 2015.
Yet it remains unclear how the EU can achieve the delicate balancing act of establishing freer trade links while maintaining its strong stance on Myanmar.
Steinmeier will personally express the European concerns to Myanmar's foreign minister U Nyan Win, diplomats said.
But his message is likely to fall on deaf ears as Myanmar has repeatedly refused to implement reforms demanded by its bigger ASEAN neighbours and continues to keep pro-democracy leader Aung San Suu Kyi under house arrest.
Thailand meanwhile is expected to use the meeting to inform the EU how it has emerged from a military coup last September.