We need to determine your residency status for tax
purposes (do not confuse with the residency status for immigration purposes)
If you are a resident for tax purposes - you will be taxed on all worldwide income (regardless of its source).
If you are a non-resident for tax purposes - you may be taxed only on income from US sources.
Please see for reference IRS publication 519 - http://www.irs.gov/pub/irs-pdf/p519.pdf for rules to determine if you are Nonresident Alien or Resident Alien
If you sell the property - you will recognize a gain or a loss = (selling price) - (basis - mainly your purchase price) - (selling expenses)
Because you owned the property for less than a year - it will be short term capital gain taxed at your regular tax rate.
You may use structure your transaction a as section 1031 "like-kind" exchange to defer (not avoid!) taxes - if that is an investment property or business property.
You may use the section 1031 regardless of your residency.
You may not use the section 1031 if the condo is your personal property.
Let me know if you need any help.
Edited by LEV on 5/1/2010 at 7:02 PM EST