One can ask for an extension/delay in disclosing results by contacting the ClinicalTrials.gov staff (email@example.com), but the request would need to meet their definition of “good cause” and publication issues are generally excluded from that definition. The data should be reported on ClinicalTrials.gov as soon as possible. Communication with the journal regarding the legal obligatory requirements may also be useful. It’s unlikely that the journal would refuse a manuscript when the institution/investigator is mandated by law to disclose publicly. However, if the trial was not registered according to the journal requirements (generally prior to enrollment of first participant), the journal may take issue with that and reject the manuscript on that basis.