I submitted a paper to an IEEE journal. The editor provided the following review:
Based on the enclosed set of reviews this manuscript is not acceptable for publication in its current form, but may be acceptable after being thoroughly reworked. If you choose to resubmit, please send the reworked manuscript no later than 07-Mar-2019, but preferably as soon as possible. The sooner we receive the resubmission, the better the likelihood that we can utilize the same editor and reviewers. If an extension is needed for any reason, please contact ... with an expected date for the resubmission. Your resubmitted manuscript will require an additional full round of review, but as stated above, we will make every effort to utilize the previous reviewers if possible. Please be sure to mention the original paper number and include a point-by-point response to the reviewer comments in your cover letter and/or File Upload section.
Does that mean "Reject" or "Major Revision"? What is the difference between this decision and reject? If I decide to submit the paper to another journal, should I withdraw the paper from the first journal?