Pressure is mounting on Claudia Sheinbaum, Mexico’s president, after two former top officials from the country’s Sinaloa state – both members of her Morena party – gave themselves up to US authorities over alleged ties to the Sinaloa cartel.

The state’s former security minister, Gerardo Mérida Sánchez, crossed the border into Arizona last week and was taken into custody by US marshals, Mexico’s security ministry said. Sinaloa’s former finance minister, Enrique Díaz Vega, was taken into custody in New York.

Both Mérida and Díaz were charged last month as part of the indictment of 10 Sinaloa officials including Governor Rubén Rocha Moya for alleged ties to the powerful Sinaloa cartel, accusing them of aiding in the massive importation of illicit drugs into the United States.

Moya has called the charges “completely untrue and without any basis”. Meanwhile, Sheinbaum has resisted extraditing the former governor, repeatedly requesting more evidence from US authorities.

On Monday, Sheinbaum maintained her defiant stance on national sovereignty, and denied any links between her government and organized crime.

“We’re not going to cover for anyone under any circumstances,” she said. “But why [is the US] so interested in Mexico? They should address their own problems there first. They need to focus on their own issues, first and foremost, drug consumption and the flow of weapons.”

But with two high-ranking officials now in US custody, it will become increasingly difficult for Sheinbaum to protect both her party and Moya, despite his being a close ally of her mentor, former president Andrés Manuel López Obrador.

“There is a growing perception in Washington that she’s playing for time and kicking the can down the road, but reality is going to overtake her,” said Arturo Sarukhán, a former Mexican ambassador to the US. “There’s now a greater possibility that others among those 10 will try and strike a bargain with US law enforcement and then you have no control as to what information is being shared with whom, and that could be a ticking timebomb for Morena.”

The fact that the two former top officials surrendered rather than waiting for extradition, also offers weight to the justice department’s initial indictment, analysts said.

“If they were empty accusations, without any basis, then no way you’d turn yourself in,” said Eduardo Guerrero, a Mexican security analyst.

Meanwhile, having both former officials in custody will help strengthen Washington’s efforts to build a case against the Sinaloa governor, according to Guerrero.

“Both of them know a lot about Rocha Moya,” he said. “They’re going to offer up a whole lot of evidence.”

Sheinbaum is also likely to contend with further accusations against officials within her party – and soon. Last week, Terry Cole, the Drug Enforcement Agency (DEA) administrator, testified before the US Senate and said that Rocha’s indictment was “just the start”.

On Friday, the New York Times reported that the Trump administration had instructed federal prosecutors to use terrorism statutes to go after corrupt Mexican officials. The directive, according to the New York Times, was announced by associate deputy attorney general Aakash Singh.

“We should be tripling the number of indictments of corrupt government officials who are using their power and their positions to enable terrorists and monsters who traffic in misery and poison,” Singh told colleagues, according to an unnamed source cited by the New York Times.

For months, Sheinbaum had appeased Washington by acquiescing to Trump’s demands, sending thousands of troops to the border to control immigration and handing over nearly 100 cartel members to face justice in the United States.

But relations began to fray in recent weeks over revelations that CIA agents have been operating in Mexico without the federal government’s knowledge, including reports that the US agency was involved in the assassination of a mid-level cartel member in March.

This increased pressure from Washington by going after current officials, including those within the governing Morena party, has pushed Sheinbaum and her relationship with Washington to the limit.

“We’re on the brink of an abyss, this is being the proverbial dominoes folding one after the other,” said Sarukhan.