British officials will stop attending most EU meetings from 1 September, except for those on "matters of ongoing national interest" such as security, the government said.
The Brexit ministry said in a statement that the time spent preparing for the meetings in Brussels would be better used in readying the country for leaving the European Union on 31 October.
"This decision reflects the fact that the UK's exit from the EU on 31 October is now very close and many of the discussions in EU meetings will be about the future of the union after the UK has left," the ministry said.
The ministry added that it made sense to "unshackle officials from these EU meetings to enable them to better focus their talents on our immediate national priorities".
"This decision is not intended in any way to frustrate the functioning of the EU. The UK's vote will be delegated in a way that does not obstruct the ongoing business of the remaining 27 EU members," it added.
Brexit Secretary Steve Barclay said: "From now on we will only go to the meetings that really matter, reducing attendance by over half and saving hundreds of hours."
The ministry said decisions on whether or not to attend a particular meeting would be made on a case by case basis.
British Prime Minister Boris Johnson, who came to power nearly a month ago, has promised to take Britain out of the EU on 31 October with or without a divorce deal with Brussels.
EU officials have rejected Mr Johnson's demand to scrap the backstop part of the deal, which was agreed by his predecessor Theresa May and has been voted down by Britain's parliament.
Sending 🇬🇧 officials to 🇪🇺 meetings that don't affect us is not the best use of their time. From 1 September we'll only go to meetings that are vital to our 🇬🇧 interests - freeing our people to focus on our future relationships. #Brexithttps://t.co/CCf1ASrxqY— Steve Barclay MP (@SteveBarclay) August 20, 2019