Mexico and the United States faced fresh diplomatic tensions on Friday after talks failed to end a disagreement over Mexican President Andres Manuel Lopez Obrador's controversial energy reforms.

Lopez Obrador rejected the idea of allowing a special US team to monitor the reform process, a day after meeting Washington's climate envoy John Kerry.

"Imposing a group to watch us, to observe us, no one will allow that. Maybe in other times, with submissive governments," Lopez Obrador told reporters.

"There is a big difference between listening, informing, talking, communicating … and imposing a group to watch us," he added.

Despite the differences, Lopez Obrador described the meeting with Kerry, which lasted several hours, as "very respectful."

Kerry said after the talks that the United States would create a team led by US Ambassador to Mexico Ken Salazar to work with the White House and his own office on the issue.

The group would "try to make sure that whatever comes out of the reform effort will reflect the best ability to try to move forward," he told reporters during his third visit to Mexico since October.

The reforms being discussed in Mexico's Congress seek to strengthen the state-owned electricity provider and roll back the effects of liberalization that Lopez Obrador says favored private companies.

That has prompted warnings that Mexico is in danger of violating its commitments under a North American trade deal with the United States and Canada.

Critics say the reforms also favor polluting fossil fuels over renewable energy.

"Mexico's energy policies damage the environment, US business and investor interests in multiple sectors, and hamper joint efforts to mitigate climate change," US Trade Representative Katherine Tai said last month according to a statement from her office.

The reforms would ensure that the state-owned Federal Electricity Commission (CFE) has at least 54 percent of the electricity market — compared with 38 percent now — and the private sector no more than 46 percent.

The Mexican government says the changes are needed to prevent soaring power prices and to tackle corruption.