Donald Trump has offered condolences to Mexico’s president one week after the country’s worst earthquake in a century, claiming he had been unable to reach Enrique Peña Nieto for several days because of bad mobile phone reception.

Trump’s condolences represent his first public comments on the earthquake, which took place last Thursday and left an estimated 2.5 million people in need of assistance. Mexico’s minister of agriculture, Jose Calzada, said on Tuesday that the death toll had climbed to 98 people, mostly in the southern state of Oaxaca.

Several US mayors and members of Congress shared their condolences with Mexico in the immediate aftermath of the 8.2 earthquake, as did Canadian prime minister Justin Trudeau. But the White House did not mention the earthquake until Thursday afternoon.

“Spoke to President of Mexico to give condolences on terrible earthquake,” Trump said on Twitter. “Unable to reach for 3 days b/c of his cell phone reception at site.”

Peña Nieto has travelled twice to areas affected by the quake, but has also spent time this week in the national capital.

On Monday he flew to Chiapas state in the afternoon but returned to Mexico City that night. He was in Mexico City on Wednesday morning, before travelling again to Oaxaca and Chiapas states to oversee earthquake relief. Mobile service in the region was working without serious incident, according to accounts on social media.

And Peña Nieto’s Twitter feed has been active since the earthquake. The account has shared dispatches from disaster sites and photos of the the president visiting the affected areas, often photographed by dozens of people carrying cellphones.

It is customary for the US to send messages of condolences to countries hit by natural disasters, and the White House’s silence did not go unnoticed – especially because Mexico had just offered the US aid for disaster recovery.

In late August, Mexico said it would provide food, generators, medical staff and other aid to help victims of Hurricane Harvey in Texas, near the border between the two countries. Mexico withdrew its offer after its own natural disaster.

“Given these circumstances, the Mexican government will channel all available logistical support to serve the families and communities affected in the national territory,” the foreign ministry said in a statement.

Trump’s explanation for his slow reaction was greeted with scornful disbelief in Mexico – even by critics of Peña Nieto.

“Lies, lies and more lies. Not bad cellphone reception; tardy reaction from bad US president,” tweeted political commentator Denise Dresser.

Peña Nieto’s office confirmed that the two men had spoken on Thursday, but made no reference to any communication problems.

Trump’s message arrived the same day a Pew Research Center poll showed that more Mexicans view the US unfavorably than at any time in the past 15 years. Nearly 65% of Mexicans surveyed said they have a negative opinion of the US.