The UK government has established working groups and "high-level dialogues" with at least 15 countries, the Department for International Trade confirmed to IBTimes UK on Wednesday 29 March.

The news comes on the same day Prime Minister Theresa May plans to invoke Article 50 of the Lisbon Treaty and trigger Brexit talks with the EU.

The process will start once Sir Tim Barrow, the UK's chief representative to the EU, hand-delivers a letter to the EU Council.

The institution's president Donald Tusk has promised to reply within 48 hours and a summit of the 27 other EU leaders has been scheduled for 29 April.

The top politicians will decide on the guidelines EU Commission negotiator Michel Barnier and his task force are given for the two-year-long talks.

May has revealed that she will not seek to maintain the UK's full access of the EU's single-market and seek to barter a "unique" customs relationship with bloc, which will allow Britain to make its own free trade agreements – something that the UK, as a member of the EU, is not currently able to do.

As of 21 March, nine working groups and dialogues have been announced publicly. You can view those countries below.

Australia

"Both of us want a future FTA to generate new trade and investment opportunities. We will prioritise consultation and outreach to our respective stakeholders to seek their input to the work of the working group," Australian trade minister Steven Ciobo and International Trade Secretary Liam Fox said in September 2016.

Heritage Foundation's trade freedom ranking for 2017: 48th-tied.

China

"The mutual benefits are clear. China is the world's second largest economy; UK exports to China have grown rapidly and Britain is home to more Chinese investment than any other European country," Chancellor Philip Hammond said in November 2016.

Heritage Foundation's trade freedom ranking for 2017: 116th.

Gulf Cooperation Council (Bahrain, Kuwait, Oman, Qatar, Saudi Arabia, UAE)

"Free trade makes us all richer. It creates jobs. It increases investment. It improves productivity. It transforms living standards and creates opportunities for all of our citizens," May told the GCC in December 2016.

Heritage Foundation's trade freedom ranking for 2017: Bahrain 65th-tied, Kuwait 88th, Oman 54th, Qatar 63rd-tied, Saudi Arabia 94th, UAE 60th-tied.

Israel

"We are enhancing our cooperation in economics, in technology, in security, in cooperation in the field of cyber, in many, many other areas. And we also seek a world that's secure and peaceful, and I look forward to discussing both of these things with you," said Israeli Prime Minister Benjamin Netanyahu in March 2017.

Heritage Foundation's trade freedom ranking for 2017: 11th-tied.

India

"We have an agreement with the Indian government to work with them on our trade relationship. What that means is more trade for British businesses, more jobs and investment in the UK and that's good for the whole country," May said in November 2016.

Heritage Foundation's trade freedom ranking for 2017: 120th-tied.

New Zealand

"We're ready to negotiate a high quality free trade agreement with the UK when it's in a position to do so," New Zealand Prime Minister Bill English said in January 2017.

Heritage Foundation's trade freedom ranking for 2017: 15th-tied.

Norway

"The Norway-UK partnership is strong, particularly in trade and business. We have agreed to work towards maintaining our close trade relationship in the coming years," Norwegian trade minister Monica Mæland said in November 2016.

Heritage Foundation's trade freedom ranking for 2017: 13th-tied.

Turkey

"We are today announcing a new and unique government-to-government agreement between Turkey and the United Kingdom that sets a new framework for cooperation and dialogue between our governments including the defence ministries and air forces," May said in January 2017.

"And we have also agreed to establish a trade working group to explore ways in which we can improve Turkish-UK trade."

Heritage Foundation's trade freedom ranking for 2017: 87th.

South Korea

"A formal working group of ministers from the two countries will meet as many as four times a year to discuss removing barriers to commerce and prospects for 'future, ambitious trade opportunities' after the UK exits the EU," Bloomberg News reported in December 2016.

Heritage Foundation's trade freedom ranking for 2017: 86th.

USA

"A free and independent Britain is a blessing to the world and our relationship has never been stronger. Both America and Britain understand that governments must be responsive to everyday working people, that governments must represent their own citizens," President Donald Trump said in January 2017.

"Madam Prime Minister, we look forward to working closely with you as we strengthen our mutual ties in commerce, business and foreign affairs. Great days lie ahead for our 2 peoples and our 2 countries. On behalf of our nation, I thank you for joining us here today as a really great honour. Thank you very much."

Heritage Foundation's trade freedom ranking for 2017: 17th-tied.