Mexico’s President Claudia Sheinbaum has accused Colombia of blocking a Mexican rescue team from entering the country after Monday’s devastating earthquake.

Sheinbaum said Colombia stopped the team because its members lacked the required certification. Mexico then provided the documents requested by Colombian authorities. She said Colombia later asked for another certification.

The dispute comes as rescue teams search for survivors after the 7.4-magnitude earthquake. The disaster struck western Colombia and has killed more than 260 people. Rescue workers are racing against time to find anyone still trapped.

Colombia has denied blocking rescue teams because of political differences. The government has accepted help from the United States, El Salvador, Ecuador and Israel.

Sheinbaum said Mexico’s rescue workers are still ready to travel to Colombia. She said the team can leave as soon as Colombia allows them to enter.

“Colombia requested a certification. They are certified, but now they are asking for another certification,” Sheinbaum told reporters.

She also praised Mexico’s disaster response teams. She said they have helped with emergencies around the world. Mexico recently sent rescue workers to Venezuela after powerful earthquakes there killed more than 6,300 people on June 24.

“The rescue workers from Mexico are incredible,” Sheinbaum said.

The disagreement comes as Colombian teams continue their search for survivors. Mexico says its specialists remain ready to help, while Colombia rejects claims that it is preventing their entry.

The dispute highlights the difficulties countries can face when coordinating international help during major disasters.