YORBA LINDA, Calif. -- The final installment of secretly recorded phone calls and meetings from President Richard Nixon's White House were released Wednesday, marking a final chapter in a campaign for public access that continues as memories of Watergate fade.

The recordings cap the release by the National Archives and Records Administration of 3,000 hours of tapes Nixon recorded between February 1971 and July 1973. The final installment covers the tumultuous three months when the Watergate political scandal that would force Nixon's resignation was closing in.

Still, he moved ahead with Soviet peace talks and a thawing relationship with China.

The recordings cover April 9, 1973, to July 12, 1973 -- the day before the existence of the covert recording system was revealed to a Senate committee.

Nixon met with Soviet leader Leonid Brezhnev in June 1973 for the only summit ever recorded on a U.S. presidential taping system. The meeting was a follow-up to Nixon's visit to the Kremlin the year before and was the first attempt at U.S.-hosted peace talks with the Soviets in six years.

Nixon remains the only U.S. president to resign. He faced being removed from office by Congress for trying to hinder the government's probe of the Watergate break-in at Democratic Party national headquarters in 1972. Many of his top White House and political aides were prosecuted.

Also unveiled Wednesday were 140,000 pages of documents, including more than 30,000 recently declassified items such as an intelligence analysis of the Vietnam war. Another 700 hours of Nixon tapes remain classified or restricted and haven't been released because of national security and privacy concerns.

Previous tape releases show the president as a paranoid man. Tapes released in 2009 show, in particular, his obsession with the Kennedy family. He ordered surveillance of the late Sen. Ted Kennedy in hopes of catching him in an affair.

Wednesday's release promised to be equally revealing, with conversations between Nixon and longtime diplomat Henry Kissinger, three future presidents and Brazilian football superstar Pele.

Faced with impeachment and a possible criminal indictment, Nixon resigned on Aug. 9, 1974 -- a little more than a year after the tapes end.

"This is a really big release in volume and importance, because of the time period it covers," said Luke Nichter of Texas A&M University-Central Texas in Killeen, who runs a website cataloging Nixon's secret recordings. "This is the end of taping and this is Watergate really beginning."

The recordings cover a period that includes the resignation of two top White House staffers and the attorney general in one day, the appointment of a special Watergate prosecutor, and the formation of a the Senate committee that would elicit damning testimony precipitating Nixon's political demise.

Nixon nonetheless kept busy with diplomacy that yielded important peace talks with the Soviets and a thawing relationship with China -- events also reflected on the tapes.

The tapes also include material on the Vietnam peace settlement and the return of hundreds of POWs to U.S. soil.