CARACAS, Venezuela?- Venezuelan President Hugo Chavez turned to philosophy and Twitter to describe his efforts to beat cancer on Monday, summoning the words of German philosopher Friedrich Nietzsche.

"I find myself before my highest mountain and my longest walk," Chavez said in a message posted on his Twitter account. "That's how Zarathustra spoke!"

That quoted a passage from Nietzsche's treatise "Thus Spoke Zarathustra: A Book for All and None."

Nietzsche's book focuses on a prophet who reflects on his life as he descends from a mountain retreat and returns to mix with mankind. Chavez occasionally quotes the German philosopher in his speeches.

During a visit to Venezuela's largest military fort later Monday, Chavez borrowed an expression from "Los Llanos," the vast central plains region where he was born, saying that he's prepared to confront the difficulties that lie ahead.

"The man from the plains is the size of the task before him," Chavez said, recalling anecdotes from his days as a soldier and briefly breaking into song during a live television broadcast.

The TV broadcast was the president's first public appearance since Saturday.

Chavez's government also said Monday that the president is recovering quickly after undergoing surgery last month that removed a cancerous tumor.

Chavez remarked on his health during a telephone conversation with Russian President Dmitry Medvedev on Sunday while exercising outdoors, the Foreign Ministry said in a statement.

Chavez told the Russian leader "that he has experienced a rapid recovery from the complex operation," the Foreign Ministry said, adding that the president has been undergoing a first phase of rehabilitation.

It said that "has generated an optimal scenario" as he starts a second phase of recuperation, adding that Chavez now has a "feeling of realistic optimism."

Chavez has said he underwent surgery in Cuba on June 20 to remove a tumor from his pelvic region. Chavez hasn't said what type of cancer is involved.

Since his return to Caracas on July 4, the 56-year-old president has slowed his normally heavy agenda and has limited the length of his televised speeches, saying he is under strict orders from his doctors.

The Foreign Ministry said Medvedev wished Chavez a speedy recovery and told him he could count on Russia's help if needed. It said Medvedev told him that Russian Foreign Minister Sergey Lavrov plans to visit Caracas on August 22-23, and that he hopes to host Chavez in Moscow soon.

Chavez's remarks followed other optimistic assessments by his allies.

Bolivian President Evo Morales, who visited the Venezuelan leader last week, told Colombian radio station Caracol on Sunday that Chavez "has survived the bad moment, the worst."

Aristobulo Isturiz, a prominent member of Venezuela's ruling party, dismissed allegations from opposition politicians that Chavez is not fit to govern due to his illness. He told a news conference on Monday that Chavez is diligently attending to his duties as president.

"The president is governing, and he has not stopped governing for a single moment," Isturiz said.

Another ally, former Venezuelan Vice President Jose Vicente Rangel, said in an interview with the Colombian magazine Semana that "for the moment he's not going to need chemo."