US climate envoy John Kerry called Wednesday for an "open and competitive" energy market in Mexico, where planned reforms have alarmed foreign investors and environmentalists alike.

Washington has stepped up pressure on Mexico over President Andres Manuel Lopez Obrador's push to boost the state's role in the energy industry -- moves critics say favor fossil fuels over renewable energy.

Meeting with Lopez Obrador and other top officials in the Mexican capital, Kerry said the country could "play a vital, extraordinary role" in efforts to tackle the climate crisis.

"Mexico is blessed with assets that many other countries don't have -– great wind, great sun, geothermal, hydro, and fossil fuel," he told reporters.

"What we want to do is work with Mexico in a way that will strengthen... the ability of the marketplace to be able to be open and competitive," Kerry said.

The reforms championed by Lopez Obrador seek to strengthen the state-owned electricity provider and roll back the effects of liberalization that the leftist president 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.

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.

In November, Lopez Obrador's ruling party pushed back its deadline for the approval of the reform bill until April, following a backlash from the United States, Canada and foreign investors.

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

Kerry said Washington respected Mexico's sovereignty and was ready to help it transition to cleaner energy sources.

"I know the president has embarked on some reforms that are important to him and to the country," he said.

"The United States is prepared to be as helpful as we can be. Not because it advantages us but because we are all in this together," he added.

Mexican Foreign Minister Marcelo Ebrard said Mexico would "join these efforts as they have already been agreed" upon by Lopez Obrador, US President Joe Biden and Canadian Prime Minister Justin Trudeau, who met in Washington in November.

Subsequently, the foreign ministry said in a statement that the US and Mexico had agreed to set up a "High Level Group on Renewable Energies and Climate Change", which will tackle emissions and deforestation and promote renewable energy.