"I pay tribute to the help of the DRC authorities and Congolese Insitute of Nature Conservation", he added.
The 2 tourists were kidnapped while visiting the Virunga National Park where mountain gorillas are a tourist attraction.
Park ranger Rachel Masika Baraka was killed by the kidnappers; a driver was injured and released.
Foreign Secretary Boris Johnson said he was "delighted to announce" their release.
A 25-year-old park ranger travelling with them was killed and their driver was also taken captive, a park spokesman said.
Congolese authorities are working with the Foreign Office to repatriate the British tourists, according to a park statement.
A female park ranger was killed in the attack, local media reported.
The pair, whose release was arranged by guards at Virunga National Park, are uninjured and no ransom was paid, ITV News Africa Correspondent John Ray said.
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"I pay tribute to the DRC authorities and the Congolese Institute for Nature Conservation for their tireless help during this awful case", Johnson said in a statement.
Virunga is a UNESCO world heritage site covering 3,000 square miles on the country's border with Uganda and Rwanda.
A park ranger who tried to protect them was shot dead by the attackers.
The park is home to around a quarter of the world's critically endangered mountain gorillas and other endangered species, as well as lions, elephants, hippos and rare birds.
The Foreign Office now - and before the kidnapping - advises against travelling to the area.
"Tourists in eastern DRC have been known to be left very vulnerable as a result of trying to travel independently without escorted transport, and the risk of kidnap or injury as a result of armed or criminal activity remains high".
It said that United Kingdom government staff were not always in the area and the British embassy's ability to offer consular assistance could be "severely limited".