His son Rafael Pelli, a partner in his father’s New Haven-based firm Pelli Clarke Pelli Architects, confirmed the death but did not provide a specific cause.

The Argentine-born Mr. Pelli received some of his profession’s highest awards, served as dean of the Yale School of Architecture and maintained a creative pace that often placed him on lists of the most influential architects into the 21st century.

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His projects spanned a broad sweep of form and function: stately commercial headquarters, angular arts centers, a terraced-glass addition to New York’s Museum of Modern Art, and the sun-drenched north terminal at Washington’s Reagan National Airport.

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But a unifying chord — and perhaps his greatest contribution to the architectural canon — was what he called his attempts to keep a building’s “soul” and “skin” in harmony with its surroundings through a careful selection of materials, styles and details.

Mr. Pelli’s Art Deco-inspired Wells Fargo Tower blends with the granite-and-brick cityscape of downtown Minneapolis. And his Adrienne Arsht Center for the Performing Arts is a ziggurat of aqua-tinged light and jagged angles intended to capture the Miami sun and symbolize the unpredictable flourish of creativity.

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In New York, one of the showcases of Mr. Pelli’s shifting styles, the slim, 60-story Carnegie Hall Tower features mixed brick tones to echo the weatherworn hues of older buildings south of Central Park. “This slender, elegant slab is like a dancer among thugs,” Time magazine architecture and design critic Kurt Andersen wrote in 2001.

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Farther downtown, the solid World Financial Center (now Brookfield Place) complex and palm-filled Winter Garden evoked the greed-is-good swagger and opulence of 1980s Wall Street. (The complex underwent significant reconstruction work from damage in the Sept. 11, 2001, terrorist attacks.)

“We should not judge a building by how beautiful it is in isolation, but instead by how much better or worse that particular place . . . has become by its addition,” Mr. Pelli told Architectural Digest in 1988.

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There are those who believe Mr. Pelli sometimes fell short of that credo.

When Mr. Pelli’s firm cut the ribbon on the 50-story One Canada Square tower in London’s Canary Wharf in 1991, some British architecture critics cringed at the stainless steel skyscraper, then London’s tallest at nearly 800 feet, as grossly out of place. Prince Charles bluntly told Mr. Pelli: “I personally would go mad if I had to work in a place like that.”

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The Pacific Design Center also has been a frequent subject of design debate since its main building, nicknamed by locals the “blue whale,” opened in 1975. Two others — one vivid green and the other playful red — later completed the campus.

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His other seminal structure in California was the 1,070-foot Salesforce Tower, which opened in 2018 and dominated the city’s skyline and became the tallest office building west of the Mississippi. The tapered steel and glass structure serves as headquarters of the cloud computing company Salesforce.

“Pelli’s career shows that you can be a modernist without being tied to a rigorous vocabulary of form or structure, or curtain walls of glass,” said Carol Willis, an architectural historian who founded the Skyscraper Museum in New York. “He embraced the full spectrum of materials — be it stone or stainless steel, or color and pattern — while remaining true to the spirit of modernism.”

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César Pelli was born Oct. 12, 1926, in the city of San Miguel de Tucumán in northwestern Argentina. His parents — his father was a civil servant, and his mother was a teacher — amassed a sizable library that included illustrated volumes on art, which Mr. Pelli pored over in his youth.

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After graduating in 1949 with an architecture degree from the University of Tucumán, he helped design low-cost housing projects for a state-run development company. On a whim, he applied for a scholarship in 1952 for advanced study in architecture at the University of Illinois at Urbana-Champaign.

He and his wife, the Spanish-born landscape architect and scholar Diana Balmori, found the slower-placed, small-city atmosphere comforting and similar to their provincial life in Argentina. “If I had landed in Chicago or New York, I don’t know if we would have survived,” he said in the Architectural Digest interview.

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Mr. Pelli obtained a master’s degree in 1954 and almost immediately began work on a Masonic temple project with the Finnish-born Eero Saarinen. That began a fruitful professional relationship between Saarinen and Mr. Pelli, who also assisted Saarinen with the iconic TWA terminal at New York’s John F. Kennedy International Airport (then known as Idlewild Airport). The terminal’s flowing, Space Age lines awed the world in 1962 as a symbol of American progress and forward-looking invention.

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Saarinen’s emphasis on lean and unified exteriors also had a deep impact on Mr. Pelli’s view of what he later called the “skin” of his designs.

Mr. Pelli, who worked in the firm’s Michigan and Connecticut offices, stayed with the company for three years after Saarinen’s death in 1961. As a newly minted U.S. citizen in 1964, he shifted to Los Angeles at a moment of explosive growth and experimentation for builders in Southern California.

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Mr. Pelli relished the blank-canvas freedoms. As a partner in one of the city’s expanding design-engineering firms, Daniel, Mann, Johnson & Mendenhall (DMJM), he became a trailblazer in new methods of glass cladding in the mid-1960s.

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“Glass is fragile as the wings of a butterfly,” he told the Los Angeles Times in 1990. “It’s alternatively opaque and transparent, ephemeral and light-sensitive, reflecting the changes of the sky color and tone.”

Buildings such as a Federal Aviation Administration office in Lawndale, Calif., were encased in mirrored glass that captured the kaleidoscope of sky and scenes around it — and served as a real-time panorama of the area’s rapid changes. In another leap, Mr. Pelli used dark gray glass sheaths to enclose the Century City Medical Plaza in Los Angeles.

For the Comsat Laboratories in Clarksburg, Md., designed in 1967 as one of his last DMJM projects, Mr. Pelli combined several features of his earlier lightweight-skin structures, including the use of glass and aluminum.

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Mr. Pelli later jumped to a larger Los Angeles-based firm, Gruen Associates, which had wider reach, and in 1976 teamed with Norma Merrick Sklarek to unveil the sleek and linear U.S. Embassy office building in Tokyo.

For Mr. Pelli, 1977 was an eventful year. He formed his own company in New Haven, César Pelli & Associates, was selected as Yale School of Architecture dean — a post he held for seven years — and won the commission for the gallery extension and 52-story residential tower at MoMA. Reviews were mixed for Mr. Pelli’s MoMA design, which brought intense scrutiny befitting one of New York’s most prized institutions. Some observers praised the flood of natural light into the gallery and appreciated the Scandinavian-style minimalism of the tower’s interior trappings.

But the design scholar Vincent Scully — in a 1988 revised version of his classic “American Architecture and Urbanism” — said the high-rise “severely compromises the privacy and scale” of the MoMA sculpture garden below.

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The project ushered in a reach for taller projects and bigger commissions for Mr. Pelli.

He increasingly put his mark on skylines around the world: the 60-story Bank of America corporate headquarters in Charlotte (1992); the 68-story Cheung Kong Center in Hong Kong (1999); and the 72-story Landmark completed in 2013 in Abu Dhabi, the United Arab Emirates.

The literal pinnacle of Mr. Pelli’s push skyward was perhaps his most innovative. The dual 1,483-foot Petronas Towers in Kuala Lumpur, Malaysia, held the title of world’s tallest from 1998 to 2004. It was the first No. 1 skyscraper in the 20th century outside the United States — a powerful sign of Asia’s emerging economic clout. (Petronas beat Chicago’s Sears Tower, now called the Willis Tower, by about 30 feet.)

But for Mr. Pelli, a principal accomplishment came with his use of Islamic- and Asian-inspired geometric patterns as homage to Malaysia and its Muslim heritage.

Mr. Pelli’s design — which brings an evocative play of light and shadow — seems almost “organic, like fantasyland flowers,” Washington Post architecture critic Benjamin Forgey wrote about a 2001 retrospective of Mr. Pelli’s work at the National Building Museum.

Four years earlier, a review by Forgey generally applauded the new Pelli-designed terminal at National Airport, celebrating the flood of light from the glass domes and the prominence of artwork including balustrade paintings, murals and sculpture walls.

The soaring arches and acres of glass drew a clear lineage to London’s former Crystal Palace, which Mr. Pelli had called the first “modern masterpiece” of the 19th century.

“There is nothing new about this,” Forgey wrote in The Post about the airport terminal in 1997. “Washington, like Rome or practically any other city you can think of, is filled with buildings where the art contributes harmoniously to the architecture.

“But it is a habit that has been badly broken in the past ­half-century or so,” he continued, “and the new National terminal represents, in effect, a backward step in the right direction.”

Among Mr. Pelli’s many honors was his election in 1982 as a member of the American Academy of Arts and Letters, and winning the prestigious Gold Medal from the American Institute of Architects in 1995.

His wife died in 2016. In addition to his son Rafael, of Manhattan, survivors include another son, Denis Pelli, also of Manhattan; a brother; and two granddaughters.

Mr. Pelli often recounted a story of walking down Broadway in 1990 and running his eyes over the Manhattan cityscape. “I suddenly noticed this burst of golden light ahead,” he said. “It was this building of mine” — the Carnegie Hall Tower.

But Mr. Pelli insisted that his overall goal concerned how people interacted with his buildings, rather than how the buildings were admired from a distance.

“There is nothing quite so pleasurable for me as to visit my buildings when they are finished and occupied,” he wrote in a 1988 essay. “It is like being part of a miracle taking place. Months and even years of caring and dreaming become a reality.”