The hearings are expected to resume on 18 May, but the lawyers will argue on Monday that they have not had full access to their client. The lawyers who represent the United States also agree that the hearings should be rescheduled, the statement said.
Assange was stripped of asylum in the Ecuadorian Embassy in London and arrested by British police a year ago. The whistleblower is now on remand at the Belmarsh high-security prison for breaching bail.
The UK is currently mulling over extraditing him to the United States to potentially face a decades-long sentence on espionage charges.
In the meantime, human rights organisations have also raised concerns over Assange's health, as the prison has already reported coronavirus cases and fatalities among the inmates.