In order for a marriage to be valid, there must be agreement from both parties, and the presence of the woman’s wali (guardian) and two Muslim witnesses of good character, and there should be no impediments in the case of either partner.
If these conditions are met, and the contract is done by means of the proposal and acceptance by the wali and the husband, then the marriage is done. See question no. 2127. Recording and documenting the marriage are done only to protect people’s rights and to avoid disputes.
Based on this, if you agree to do the marriage in the manner described above, and on the basis that you will delay the registration and documentation until you go back to your country or until it becomes easier for you to go to an Islamic center, then there is nothing wrong with that.
You should announce the marriage, and inform your neighbours and relatives of it, so that legitimate marriage will be made distinct from illicit relationships.
It is preferable to hasten to register the marriage at the first opportunity, and strive to do that so as to ward off any suspicion and so as to protect people’s rights, especially if Allaah blesses you with children.
And Allaah knows best.