"LONDON, Nov, 11?ÛÓTreasury. Secretary Donald T. Regan today refused to rule out cuts in defense spending and Medicare, or a tax increase, as part of the effort to trim the budget deficit.</br></br>?ÛÏWell, what we?Ûªre saying is tax increases only as a last resort,?Û? Regan said in an interview on ?ÛÏThe Business Program,?Û? broadcast on Britain?Ûªs commercial TV channel.</br></br>In the interview taped Thursday, two dnys after the president won a landslide reelection victory, Regan said he was confident the administration will find excesses in the spending side of the budget.</br></br>?ÛÏYou cannot tell me that there?Ûªs no room left to cut the federal budget in the United States,"" said Regan. ""Absolutely preposterous. There are billions there that can be cut.?Û?</br></br>Asked whether the cuts would include defense, Regan replied, ""As far as the Defense Department is concerned, no.?Û?"