The comments by the IMF's representative in Kinshasa, Philippe Egoume, was the latest development in a long-running dispute over the corruption-plagued mining industry which is overseen by a public company.
"We have a disagreement with the authorities, who prefer to publish recent contracts but not the old ones," Egoume said during an online news conference.
"In our of view, all the contracts should be published."
DR Congo is one of the main producers globally of valuable minerals such as copper, gold, coltan and cassiterite.
Their extraction and export is handled by joint-venture contracts between the state company Gecamines and around 15 foreign businesses.
In 2012, the IMF suspended its programme with the country under former president Joseph Kabila because of what it said was a lack of transparency in Gecamines's contracts.
One of Gecamines' foreign partners, the Israeli billionaire Dan Gertler, has been under US sanctions since December 2017 for contracts which Washington says were obtained through "corruption and misconduct".
The IMF also called on Kinshasa to provide a "realistic budget" for 2021.
The government under new President Felix Tshisekedi has forecast a budget of 11 billion dollars in 2020, twice the amount set for the previous year.
Even before the coronavirus pandemic hit the world's economies, the IMF had described those figures as unrealistic.
Egoume said it was too early to say how much money the next IMF aid programme would involve.
He said the IMF had paid out 360 million dollars in December and 363 million dollars in April to help Congo cope with the coronavirus outbreak.