(Adds credit ratings context)
MEXICO CITY, June 11 (Reuters) - The Mexican government has one year to restore the investment grade credit rating of national oil company Pemex, presidential chief of staff Alfonso Romo said on Tuesday, after Fitch downgraded the company last week.
The state producer's high debt load and expensive plans pushed by President Andres Manuel Lopez Obrador continue to stoke investor uncertainty.
"We are going to do everything possible so that Pemex's investment grade rating is restored," Romo said at a conference. "We have one year."
For months, the credit rating agencies have criticized Lopez Obrador's plan to construct an $8 billion refinery and questioned whether Pemex can significantly boost crude output while shunning private partners.
Reporting by Stefanie Eschenbacher, editing by Hugh Bronstein, Chizu Nomiyama and Steve Orlofsky