Sofia - Bulgarian authorities on Thursday urged UEFA to stop "tensions" after England player Tammy Abraham said his team was prepared to defy rules and walk off the pitch if they face abuse during Euro 2020 qualifiers.

Gareth Southgate's team travel to the Czech Republic and Bulgaria for back-to-back matches on Friday and Monday.

The second game, in Sofia, will be closely watched as the hosts will be playing in the Vasil Levski National Stadium, partially closed as a sanction following previous incidents of racism.

Borislav Mihaylov, president of the Bulgarian Football Union (BFU), said his association had taken "extreme efforts and measures... to ensure a fair and safe environment" since the 2011 incidents.

"I strongly suggest that the UEFA administration take measures against the build-up of unnecessary tension," he said in a letter to UEFA published online.

He added Bulgarian fans were being made "subject of public reprimand and scrutiny", demanding for it to stop.

"The Bulgarian public has in no way committed any recent infringements that deserve it to be stereotyped as 'racist' or 'hostile,'" he said.

Last month, the BFU already responded with outrage to suggestions by Southgate that his players anticipated racist abuse when they visit Sofia in Euro 2020 qualifying.

The game will be England's first visit to Bulgaria since September 2011, when Ashley Young was subject to monkey chants as the visitors won 3-0.

The BFU was fined 40,000 euros ($44,000) by UEFA for "discriminatory" chanting and because fans threw fireworks.

Bulgaria were also punished by UEFA for "racist behaviour" when they lost away to the Czech Republic on June 7 and at home to Kosovo three days later in Euro qualifying.

For the England visit, UEFA has ordered the BFU to close at least 5,000 seats at the Vasil Levski National Stadium and display a banner that reads: "#EqualGame".