Democratic Republic of Congo President Felix Tshisekedi said on Monday that a U.S.-mediated peace deal signed with Rwanda in June has not calmed fighting in eastern Congo, though he thanked President Donald Trump for attempting to end the conflict.

On June 27, U.S. mediators brokered the peace deal between Congo and Rwanda aimed at ending the support that Washington and U.N. experts say Kigali provides M23 rebels.

The Trump administration has said it is eager to end fighting that has killed thousands this year and attract billions of dollars of Western investment to a region rich in tantalum, gold, cobalt, copper, and lithium. The deadline to implement part of the U.S. deal is this month.

Despite his support for U.S. mediation, it "does not mean that we will auction our mineral resources," Tshisekedi told reporters in New York.

"We will, as part of this partnership, be working in the development of the mining sectors, developing the value chain, developing infrastructure with a particular emphasis on energy," he said.

Tshisekedi said the country had signed a strategic partnership with China. "Today, we are negotiating a similar partnership with the USA. And we hope that we will complete it," he said. He did not provide substantial details about the partnerships.

Congolese officials say the success of the deal hinges on Rwanda ceasing its support for M23, which Kinshasa accuses of atrocities in the east. M23 has disputed allegations of attacks on civilians, and Rwanda has long denied helping M23, saying its forces act in self-defence.

"(Rwanda) pretended to withdraw their troops, but actually, they are increasing their support to M23," Tshisekedi said.

In March, Qatar brokered a surprise sit-down between Tshisekedi and Rwanda's President Paul Kagame during which the two leaders called for a ceasefire. That led to direct talks between Congo and M23, though the two sides missed an August 18 deadline to reach a peace agreement.

M23 says it wants prisoners freed before talks can advance. But a Congolese government official directly involved in the talks told Reuters that prisoners could only be released after an agreement is signed.

Tshisekedi said there has been some positive development on a possible prisoner exchange.

"As a matter of fact, we are waiting for the Red Cross to give us a go-ahead to proceed with the exchange of prisoners," he said.