The declaration was signed by the foreign ministers of the countries in Washington on Friday, along with the US Foreign Minister Marco Rubio.
The purpose of the agreement is to facilitate a "path towards peace, stability, and integrated economic development" in eastern Congo-Kinshasa and the resumption of bilateral relations.
The agreement comes at the same time as the US is holding talks about investing billions of dollars in mineral-rich Congo-Kinshasa. Rwanda also said this week that it is in talks with the US about a potential mineral deal.
Mineral-rich eastern Congo-Kinshasa has been conflict-ridden for decades, but the situation has escalated in recent months since the M23 rebel group captured key strategic cities.
UN experts and several Western governments accuse neighboring Rwanda of supporting M23, which Rwanda's government denies.
