The Long War Journal, which tracks drone attacks, has counted 22 so far this year in Yemen, down from 42 last year, and 25 attacks in Pakistan, down from 46.
One attack has been reported in Somalia.
Administration officials have said that strikes have killed few civilians, but refuse to specify how many, the Los Angeles Times reported.
Obama has also pledged to make drone information more available, but the tally of how many civilians and militants are killed by drones is still not public.
The U.S. Senate Intelligence Committee voted Nov. 5 to require the administration to release the data.
"The American people should be given basic facts about mistakes when they are made, and they should also be given the rules that the government must follow when targeting and killing an American involved in terrorist activities," Sen. Ron Wyden, a committee member, said in a statement.
The panel also voted to impose other demands before the administration could authorize a strike against a U.S. citizen, the Times said, but most Republicans oppose the drone amendments, and the bill may not pass.
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