The images were captured in early to mid-April from within 113 million kilometres, using the telescopic Long Range Reconnaissance Imager (LORRI) camera on New Horizons.
A technique called image deconvolution sharpens the raw, unprocessed images beamed back to Earth.
Scientists interpreted the data to show the dwarf planet has broad surface markings - some bright, some dark - including a bright area at one pole that may be a polar cap.
"As we get closer, the excitement is building in our quest to unravel the mysteries of Pluto using data from New Horizons," said Grunsfeld.
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Also captured in the images is Pluto's largest moon, Charon, rotating in its 6.4-day long orbit.
The exposure times used to create this image set - a tenth of a second - were too short for the camera to detect Pluto's four much smaller and fainter moons.
These latest New Horizons images allow the mission science team to detect clear differences in brightness across Pluto's surface as it rotates.
"After travelling more than nine years through space, it's stunning to see Pluto, literally a dot of light as seen from Earth, becoming a real place right before our eyes," said Alan Stern, New Horizons principal investigator at Southwest Research Institute in Boulder, Colorado.
The images the spacecraft returns will dramatically improve as New Horizons speeds closer to its July rendezvous with Pluto, NASA said.
"We can only imagine what surprises will be revealed when New Horizons passes approximately 12,500 kilometres above Pluto's surface this summer," said Hal Weaver, the mission's project scientist at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland.