CHICAGO  Saying he “didn’t molt from a hawk into a dove on Jan. 20, 2009,” Defense Secretary Robert M. Gates sharply criticized Congress on Thursday for trying to push more F-22 fighter jets into the Pentagon budget than he and President Obama say the country needs.

“If we can’t get this right, what on earth can we get right?” Mr. Gates said in an acerbic, sometimes withering speech to the Economic Club of Chicago. “It is time to draw the line on doing defense business as usual.” From his point of view, that means overbuying weapons for wars the nation is unlikely to fight.

Mr. Gates, a Republican who served as defense secretary during the last two years of the George W. Bush administration, is in a standoff with the Senate over the F-22, the world’s most expensive combat plane. Mr. Gates wants to cap the number at 187, but last month the Senate Armed Services Committee approved an amendment to set aside $1.75 billion for seven more.

To the consternation of the Pentagon and the White House, liberal Democrats like Senators Edward M. Kennedy and John Kerry of Massachusetts have said they support the additional planes, arguing that their production can help preserve jobs in districts across the country.