Buffett had said in a CNBC interviewthat Yahoo's business had deteriorated significantly and that "something has to change there."
The deal would involve Pfizer paying with 11.3 of its shares for each Allergan share.
The next policy meeting will be in mid-June, when the panel will be joined by Stanley Fischer, the former Bank of Israel governor whose nomination to the Fed's board was confirmed on Wednesday by the US Senate.
Google, which is working on projects including self-driving cars and robots, has become increasingly focused on artificial intelligence in recent years.
At least five bidders have emerged for the five-year-old video service with four million users.