I am US resident working for a UN agency in SUDAN. Am I at risk of losing my PR, if I come back to US once or twice a year? What regulations apply to my situation? Thanks.

AlienTax

As a permanent resident, you need to never be out of the US for more than 6 months continuously and maintain ties to the US. Since you will be positioned outside the US, you should file for a re-entry permit (I-131). It must be filed while you are physically in the US. They are good for 2 years and will serve to let the CBP inspections officer that you did not intend to abandon your permanent residence.

You should always file your taxes in the US (as a LPR) and maintain accounts, etc. if possible. Hope this was helpful, good luck!

For clarification, the ties to the US, generally, are drivers license, mailing address, bank accounts, memberships, etc.

Very helpful. Thank you, DCcityboy.

It looks like I am already in violation of the 6 month stay outside US; but my children are in US, and I was planning to file Taxes as LPR (as I did last year). How can correct this infraction? Where can I get legal advise? Thank you. AlienTax.

You should be fine, depending on how long you have been out of the US.

Best to compile evidence of your intention to live in the US permanently. Get documentation of the ties to the US (taxes are always good), the temporary nature of the UN assignment and more importantly, evidence that your children are in the US. Be prepared to explain to the CBP inspections officer at the port of entry about your temporary assignment and your intention to remain a LPR. If you anticipate you will be outside the US again for an extended period, the next time you are physically present in the US, file for a re-entry permit. It can be forwarded to you if you are not in the US when it is approved and issued. You can always call to speak with an immigration attorney. In the worst case scenario, you are outside the US for a significant period, you can file for the SB-1 returning resident visa (circumstances beyond your control and still qualified for PR status), but that is in an extreme case. You really should be fine.

If this was helpful, rate my answer. Thanks and good luck.