(Adds India's Reliance and fresh measures in 90 days)
By Steve Holland and Alexandra Alper
WASHINGTON, Feb 5 (Reuters) - The Trump administration on Wednesday warned Venezuelan President Nicolas Maduro not to interfere with the return of opposition leader Juan Guaido and floated possible sanctions against Russia's Rosneft and other energy companies that operate in the country.
Speaking to reporters on a call before a scheduled meeting between Guaido and U.S. President Donald Trump later at the White House, a senior administration official said Guaido's security was a top priority.
"Any harm that may be caused on Juan Guaido on his return to Venezuela will have very significant consequences," the official said.
The official also warned energy companies to "tread cautiously" in their activities in the country that directly or indirectly support the Maduro government, flagging Rosneft, India's Reliance Industries, Spain's Repsol and U.S.-based Chevron Corp by name.
"We are halfway through our maximum pressure campaign ... and their activities are clearly of concern," the official said. When asked specifically about sanctions against Rosneft, the official said "everything is an option."
Rosneft, Reliance, Repsol and Chevron have emerged as the main business partners for PDVSA since the United States imposed the steepest sanctions yet on the state-owned Venezuelan company last year. Most of them share oilfields with PDVSA in Venezuela, and they also act as intermediaries for sales of Venezuelan oil to markets such as Asia.
In 2019, Rosneft was the main receiver of Venezuelan oil, followed by China's CNPC - which suspended direct purchases from PDVSA, Cuba's Cubametales and Reliance, according to PDVSA's internal documents and Refinitiv Eikon data.
Guaido, president of the opposition-held National Assembly, is recognized as Venezuela's rightful president by dozens of countries including the United States.
He was a guest at Tuesday's State of the Union address, when Trump, a Republican, praised him as a "very brave man who carries with him the hopes, dreams and aspirations of all Venezuelans." Guaido received a standing ovation from Democratic and Republican members of the U.S. Congress.
The senior administration official also described "good momentum" since Maduro's party failed to wrest control of the national assembly from Guaido last month, and said there would be some "impactful measures" within the next 30 days to further cripple Maduro's rule.
The only possible topic up for negotiation with Maduro's government was a discussion of "certain guarantees" upon his exit, the person added. (Reporting By Steve Holland and Alexandra Alper, Additional reporting by Marianna Parraga in Mexico city; Editing by Franklin Paul and Steve Orlofsky)
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