Embattled President Nicolas Maduro marks two years in power Sunday with Venezuela's deep pockets pinched hard by plummeting oil prices, Latin America's highest inflation and simmering anger on the streets.

"It is very clear that Venezuelans of all socioeconomic groups have seen their quality of life lose ground. But the poor are those who have lost the most," said economist Maxim Ross at the Universidad Monte Avila in Caracas.

Spain's foreign ministry on Wednesday summoned Venezuela's ambassador in Madrid to protest against comments made by Venezuelan President Nicolas Maduro describing Spanish Prime Minister Mariano Rajoy as "a racist."

"The government considers that these statements, insults and threats made by president Maduro against Spain are intolerable," the Spanish foreign ministry said in a statement.

President Nicolas Maduro said Tuesday he had launched a probe into reports of Panama-based Venezuelans who may have illegally obtained wealth.

Maduro, whose socialist government is in economic crisis amid historically low oil prices, said on his television show "In Touch with Maduro" that he suspects many may have settled in Panama with laundered money or breaking his rules aimed at stemming currency flight.

With a historic meeting with Cuba's president and a brief chat with Venezuela's leftist leader, President Barack Obama sought to turn the page on decades of rocky U.S. ties with Latin America.

The Summit of the Americas in Panama City became the stage for history-making diplomacy for Obama, who has intensified his engagement with the region in his second and final term in office.

U.S. President Barack Obama spoke with Venezuelan President Nicolas Maduro for the first time Saturday, telling him Washington was not seeking to threaten Caracas amid sky-high tensions.

U.S. officials said the two leaders met for a few minutes on the margins of the Summit of the Americas in Panama City, where Maduro used the stage to air his grievances about U.S. sanctions against Venezuelan officials.

U.S. President Barack Obama arrived home late Saturday, just hours after unprecedented face-to-face talks with Cuban President Raul Castro and a first meeting with Venezuelan President Nicolas Maduro.

Obama characterized his meeting with Castro -- the first sitdown between leaders of both nations since 1956 -- as "candid and fruitful," while the White House said the U.S. leader voiced support for a peaceful dialogue between Venezuela's government and the opposition during brief talks with Maduro.

A top U.S. diplomat met with Venezuelan President Nicolas Maduro earlier this week in Caracas, Washington announced, after tensions flared between the two governments in recent weeks.

The meeting with U.S. State Department Counselor Thomas Shannon occurred Wednesday, an agency spokesman said, the same day the advisor met with Venezuelan Foreign Minister Delcy Rodriguez.

Presidents Barack Obama and Raul Castro are expected to hold talks Saturday, a U.S. official said, raising the prospect of the first substantive meeting between an American and Cuban leader in more than five decades.

Obama and Castro are in Panama for the two-day Summit of the Americas, Cuba's first, raising expectations of a landmark follow-up to their historic announcement on December 17 that their countries would restore ties severed since 1961.

A massive corruption scandal at Brazil's state oil company. Protests over the presumed massacre of 43 students in Mexico. An Argentine prosecutor's mysterious death. Economies slowed by falling commodity prices.

Several of the Latin American leaders gathering at the Summit of the Americas in Panama on Friday and Saturday are facing major political headaches back home, from scandals to protests and sinking approval ratings.

Foreign Minister Delcy Rodriguez said Wednesday she pressed a visiting U.S. diplomat over Caracas' wish to have Washington revoke an order calling Venezuela a national security threat.

Rodriguez, who met with Thomas Shannon, top counselor in the State Department, urged Shannon to have Obama revoke the order.