Britain will continue to obey EU rules on negotiating trade deals as long as it remains a full-fledged member of the bloc, finance minister Philip Hammond said on Friday.
The comments were made just hours before British Prime Minister Theresa May is to sit down with US President Donald Trump to begin drawing up a free trade deal linking the countries after the UK leaves the European Union.
May's visit to Washington has ruffled feathers in Europe as it would be a violation of EU treaties for a member state to negotiate trade deals independently of the bloc.
"Britain remains a fully engaged member of the European Union," Hammond said in a response to a question on May's visit as he arrived for talks with EU finance ministers in Brussels.
Britain, which voted to quit the EU in June, is expected to launch two years of fraught exit negotiations in late March but will remain a bloc member until the divorce is done.
In the meantime, May's government is keen to start talks on a US-UK free trade agreement as soon as possible, seeing bilateral trade deals as the best hope of softening the blow of leaving Europe's single market of 500 million consumers.
May's government will "continue to abide by the rules and regulations and the laws of the European Union for so long as we are members," Hammond said.
Britain was "very mindful of our obligation under the treaty and we will follow them precisely," he said.
The EU's chief Brexit negotiator Michel Barnier on Wednesday said Britain was free to "discuss" its future trade relationship with the United States but remains bound by EU treaties as long as it is a member of the bloc.
The British government has already laid the groundwork for future free trade negotiations with India, Australia and New Zealand.