In his first interview since an armed group backed by Rwanda seized swaths of his country’s territory this year, Felix Tshisekedi, the president of the Democratic Republic of Congo, offered the United States and Europe a stake in his country’s vast mineral wealth, a sector currently dominated by China.

Congo is considered to be among the world’s wealthiest country in terms of natural resources. It provides much of the world’s coltan, which is used to power smartphones and computers. It also holds more than half the world’s cobalt reserves, used in electric vehicles.

Mr. Tshisekedi seemed eager to capitalize on this as he tries to manage a conflict he says is similar to Russia’s invasion of Ukraine. Mr. Tshisekedi has pinned his hopes on Western pressure against Rwanda, calculating that major investments in Congo — including a possible minerals deal — would bring his country much more security and stability.

China currently has far greater access to Congo’s mineral wealth than the United States, while the European Union has negotiated with Rwanda, agreeing to give it about $935 million in return for access to minerals like tin, tungsten and gold.

Mr. Tshisekedi said those minerals are plundered by Rwanda from his country, and called Europe’s deal “an absolute scandal,” accusing the European Union of being “complicit in the theft and looting of Congo.”

The European Union has argued that the deal will lead to increased regulation and greater cooperation in the fight against conflict materials. Last week, the European Parliament called for the deal to be suspended until Rwanda ceased all interference in Congo, “including exporting minerals mined from M23-controlled areas.”

Competition over Congo’s riches has long kept its population among the world’s poorest, and the weakness of its army has kept it vulnerable to outsiders.

An armed group called M23 began its lightning offensive in eastern Congo earlier this year. The group is made up of roughly 8,000 men that the United States and the United Nations say are directed and funded by Rwanda.

M23 has killed thousands of Congolese soldiers and civilians since January, capturing two key airports and two major eastern cities, Goma and Bukavu. It is currently marching toward a third.

On Thursday, the United States announced sanctions on an M23 spokesman and a Rwandan government minister for links to the violence in eastern Congo.

A thousand miles to the west in Kinshasa, Congo’s capital, Mr. Tshisekedi has been running out of options. Speaking over video call from his wood-paneled office, he said he had skipped recent peace talks on the conflict because Rwanda has insisted he speak directly to M23.

“I don’t want to negotiate with M23,” he said. “M23 is an empty shell.”

Mr. Tshisekedi accuses Rwanda of trying to disguise M23 as a Congolese armed movement, saying it is really a creation of the Rwandan military meant to defend Rwandan interests in Congo, including plundering minerals. “We’d rather talk to Rwanda,” he said.

Paul Kagame, the president of Rwanda, has denied funding or directing M23. In response to a request for comment, a spokeswoman for Mr. Kagame wrote that Mr. Tshisekedi was promoting a “tired story,” and encouraged him to “follow the road map African regional leaders have decided.”

Those regional efforts to resolve the crisis have floundered, and Mr. Kagame has also refused to attend recent peace talks. Calls by the African Union for a cease-fire have so far gone unheeded.

But the crisis is at a pivotal moment. In its sanctions announcement on Thursday, the United States warned of the prospect of a wider regional war.

This week, M23 attacked all the main Congolese military positions on the road to Butembo, a city north of Goma, according to local reports. M23 has also said it has its sights on Kinshasa. Mr. Tshisekedi has vowed to retake Goma from M23 “either through dialogue or military reconquest.”

The Trump administration has already shown interest in a deal that could ensure a stream of strategic minerals directly from Congo, Mr. Tshisekedi said. He also touted investments in major Congolese projects including a mega dam that, if completed, would be the world’s largest hydroelectric plant.

At the same time, Rwanda has cultivated relationships with Western powers — hosting major sporting events and concerts with celebrities like Kendrick Lamar — making more aggressive sanctions from the West unlikely to come quickly, analysts say.

“Leaders need to be braver,” Mr. Tshisekedi said. “It seems to me everyone’s afraid of Kagame. Why? That surprises me.”

M23 claims its mission is to protect one of Congo’s ethnic minorities.

Thirty years ago, about 800,000 civilians, mostly Tutsis, were slaughtered in Rwanda by members of the Hutu majority. After the genocide, many of the Hutus in Rwanda fled into Congo to avoid facing justice. M23 claims the Tshisekedi government is failing to protect Congolese Tutsi, known in Congo as Banyamulenge, from discrimination.

Mr. Tshisekedi has denied this. “That’s not true,” he said in the interview. “I am the first president of this country to have said loud and clear to all my compatriots that the Banyamulenge, or Congolese Kinyarwanda-speaking Tutsi, all are indeed Congolese.”

Mr. Kagame says the conflict in eastern Congo must be resolved between Congolese leaders and the rebels. He has acknowledged that Rwandan troops are present in Congo, but denies supporting M23. Fighters hostile to Rwanda in eastern Congo pose a national security risk for his country, Mr. Kagame has said.

Mr. Tshisekedi said in the interview that this was a false pretext to justify invasion. “In reality, they’re plundering Congo’s natural resources,” he said, calling Mr. Kagame a “warlord” with a “mania to be the apex predator.” According to the United Nations, M23 already controls much of Congo’s coltan.

So far, the United States has issued condemnations of Rwanda but taken little action. On Jan. 30, President Trump called the fighting in eastern Congo “a very serious problem” but declined to say more.

Experts said the sanctions announced on Thursday were a significant symbolic step — particularly those against James Kabarebe, one of Mr. Kagame’s oldest loyalists, who helped a previous incarnation of Rwanda-backed rebels seize Kinshasa in 1997.

But, analysts say, the United States could go much further, for instance by pushing the World Bank to cut Rwanda’s funding, much of which is provided by the U.S. government, and by reviewing Rwanda’s lucrative role as a supplier of troops to peacekeeping missions.

On Friday, the U.N. Security Council unanimously adopted a draft resolution that called for the withdrawal of Rwandan troops in Congo and an end to the M23 offensive.

“The only language Kagame understands is force,” Mr. Tshisekedi said. “Diplomacy is not in his DNA.”