The EU on Monday added eight officials from Myanmar's junta and three firms linked to the military to its sanctions blacklist over the country's February coup and bloody repression of protests.
Those targeted with asset freezes and visa bans included the interior, security, finance, natural resources, and transport ministers, according to listings published in the EU's official journal.
The 27-nation bloc put the state-run gem and timber enterprises on the list as they look to cut off key revenues to the junta.
It also added the Myanmar War Veterans Organisation, which acts as a reserve force for the military, to the blacklist.
The latest additions take the number of individuals and entities sanctioned by the EU to 35 since the bloc's first round of punitive measures agreed in March.
The US and Britain have also targeted key officials and enterprises in the country, but so far the junta has shrugged off Western pressure.
London on Monday also announced sanctions on the same companies as well as the military junta's ruling body the State Administration Council.
The Foreign Commonwealth and Development Office said the move to curb trade in the two high-value commodities would deprive the generals of "millions in revenue".
"The military has continued its subversion of democracy and brutal killing of civilians," said Foreign Secretary Dominic Raab.
"We will continue to hold the junta to account and sanction those responsible, until democracy is restored."
Myanmar has been in turmoil since the military overthrew civilian leader Aung San Suu Kyi and her National League for Democracy government.
A mass uprising against the putsch has met a brutal crackdown leaving more than 870 civilians dead, according to a local monitoring group.
Campaign groups welcomed the latest EU and UK sanctions. Anna Roberts, executive director of the Burma Campaign UK, said it was a way of keeping up economic pressure.
"The EU must now also look at creative ways to stop oil and gas revenue reaching the military. It is vital to continue to systematically identify and cut sources of revenue to the military," she added.
The London-based Environmental Investigation Agency (EIA), which probes transnational wildlife crime, illegal logging and deforestation, also applauded the move.
"There is now no legal source for timber, including precious teak, to be imported from Myanmar into the EU," said EIA forests campaign leader Faith Doherty.
"With these targeted sanctions, we will be able to stop the flow of hard currency to those who profit individually."