The battle of the Pentagon budget resumed yesterday as two key senators accused the Carter administration of being two-faced about the need to increase defense spending.

Sen. Sam Nunn (D-Ga.) made that complaint in a floor speech, while Sen. Ernest F. Hollings (D-S.C.) registered the same objection in an interview with The Washington Post.

Nunn, a member of the Armed Service Committee, is seen by the administration as highly influential in the fight for Senate approval of the strategic arms limitation treaty (SALT II).

"While publicly the administration is gently criticizing the Budget Committee defense cuts," Nunn complained in his floor speech yesterday, "those on the committee like Sen. Hollings leading the fight for increases are under the impression that the administration is opposing their efforts."

Hollings, in confirming this, said Jack Stempler, the Defense Department's director of congressional relations, "stonewalled me" when asked how much additional money the Pentagon needed to make up for the higher-than-expected increases in inflation.

In an earlier complaint about lack of administration support for attempts to raise defense spending, Hollings wrote President Carter that "a coalition attempted on the House side earlier this year to provide for the commitment, and the White House liaison team worked against the move."

Hollings is the point man on the Senate Budget Committee in the battle to get more money for the Pentagon by raising congressionally imposed money ceilings. Hollings also is a member of the Senate Appropriations subcommittee on defense. Nunn and Hollings said they will team up next week to try to get more money for the Pentagon.

Their plan is to raise the ceiling for national defense spending, which includes some money for the Energy Department, to provide a 3 percent, after inflation increase for fiscal 1980 and 5 percent real increases for fiscal years 1981 and 1982.

Nunn said he hopes the administration will support this effort more than it did Hollings' unsuccessful fight to raise the money ceiling just before the August congressional recess.

In his floor speech, Nunn cited reports in The Washington Post that quoted "unidentified" executives in the Carter administration as saying the Pentagon did not need all the extra billions it would receive if Nunn's proposal to increase defense spending by 4 or 5 percent every year for the next five years were adopted.

"I agree with those who state that the president should not increase defense spending solely to gain SALT votes," Nunn said. But he said "only a determined, well-planned commitment" to higher defense spending can reverse the unfavorable trends in the overall U.S.-Soviet military balance.

But rather than confront the problem head-on, continued Nunn, the administration "apparently" plans to submit a request for supplemental funds for fiscal 1980 this fall so it can live up to its commitment to increase defense spending by 3 percent over last year, after allowing for inflation.

Rather than go along with the administration's plan to submit a supplemental money request for fiscal 1980, Nunn and Hollings next week will attempt to raise that year's national defense spending ceiling from $127.4 billion to $130 billion.

The vote on the Hollings resolution will be the first test of Senate sentiment for higher defense spending since last week's disclosure that about 3,000 Soviet combat troops are in Cuba. Senate Majority Leader Robert C. Byrd (D-W. Va.) recently came out for higher defense spending, improving the outlook for the Nunn-Hollings effort next week.