President Carter has not yet approved production of the first U.S. warhead specifically designed to kill people on the battlefield through release of neutrons, a White House official said yesterday. The new nuclear warhead had been approved by President Ford.

Money to start building the so-called "enchanced radiation" warhead for the 56-mile range Lance missile is in the Energy Research and Development Administration portion of the $10.2 billion public works appropriation bill before Congress.

Even if the Lance nuclear warhead money is voted by Congress, the official said, Carter will delay production "until he has specifically approved the program."

The Lance warhead is the first practical use of a longtime experimental theory of government weapons-makers that calls for the cutting down of nuclear blast and heat in a warhead and the expansion of a killing dose of neutron radiation.

In April, 1976, according to Pentagon sources, President Ford approved funds to start building the Lance neutron warhead as the first in a new generation of tactical mini-nukes.

Money was contained in Ford's fiscal 1978 ERDA budget since that agency, as successor to the Atomic Energy Commission, pays for research and production of nuclear weapon warheads.

When the Carter administration took office, it reviewed and approved the ERDA fiscal 1978 nuclear weapons program but, according to Pentagon sources, did not go into the specifics of the Lance neutron warhead.

Though questions were not raised by Carter officials about the "enhanced radiation" Lance warhead, they did question and reject a non-nuclear version of the Lance.

The Carter administration police reviews now under way are expected to lay the groundwork for the President's decision on whether to go ahead with the Lance warhead.

The first is an overall military strategy review that has been under way for three months and is expected to be concluded within three weeks. According to informed sources, this study will set overall policy for strategic and general-purpose military forces.

"There will be an attempt to fit tactical nuclear weapons in there," a White House aide said yesterday.

In addition, ERDA and the Pentagon are in the process of winding up their annual study of the nuclear stockpile and forwarding to the White House their recommendations for new production.

Under the Atomic Energy Act, each year the President must personally approve all upcoming nuclear warhead production.

Carter is not expected to make his decisions for 1978 until November, one White House aide said yesterday.

The Lance, with regular nuclear warheads, is already deployed in Europe with NATO forces.

U.S. NATO commanders for years have pressed for a new generation of nuclear warheads to replace older ones with high nuclear yields that they believe would not be used should war break out.

The Army, however, had balked for years on the neutron warhead approach because, as one weapons expert said yesterday, "they wanted instantaneous incapacitation."

The Lance warhead now scheduled for production, this source said, apparently had convinced them "it could do the job."