Russia earned nearly $100bn (£82.3bn) from oil and gas exports during the first 100 days of the war in Ukraine, according to a report.
Revenues have been falling since March, as many countries shunned Russian supplies, but remain high, the independent Centre For Research on Energy and Clean Air (CREA) found.
It also warned of potential loopholes in efforts to curb imports from Russia.
The EU, US and UK are among those to have pledged to cut Russian imports.
