The 70-year-old former French and U.S. Open champion, who earned a reputation for controversial behaviour during his playing days, was excluded from the tie on Saturday for unsportsmanlike conduct, with an investigation under way.
"(The investigation) is ongoing. At this point, one of the principles that is important is that we want a rigorous process that is fair," International Tennis Federation (ITF) President David Haggerty said on Monday.
"We will also hear Nastase’s side of the argument. It will be a thorough process conducted in an efficient manner. I do not think you will be hearing any final decisions in the next two weeks."
Saturday's second singles rubber between Romania and Britain was briefly suspended with world number seven Johanna Konta in tears after the remarks made by Nastase.
Konta recovered her composure to finish off a victory over Romania's Sorana Cirstea and level the tie at 1-1 but Romania went on to win it andfter Konta and Heather Watson both lost on Sunday.
Britain's captain Anne Keothavong also said she was made to feel uncomfortable by "innapropriate comments" made by Nastase at the official pre-match dinner.
Nastase had already run into trouble during the World Group II playoff tie in Constanta, Romania, after allegedly making a derogatory comment about American world number two Serena Williams's unborn child.
Read the original article on Eurosport: No decision on Nastase for at least two weeks - ITF's Haggerty