The Reagan administration, addressing "confusion in other quarters," yesterday reaffirmed its support for a comprehensive and enforceable Central American regional peace treaty and for President Reagan's special Central American envoy, Philip C. Habib.

White House spokesman Larry Speakes told reporters that "the position of the United States has remained constant" through a hailstorm of critical position papers, letters of advice and expressions of alarm from conservatives and the Pentagon that has intensified as prospects of a treaty-signing have increased.

"I don't think there's been any confusion here. There's been confusion in other quarters," Speakes said.

He rejected a demand from Rep. Jack Kemp (R-N.Y.) that Habib be recalled and replaced in order to avert "a diplomatic disaster" at the so-called Contadora treaty talks, which enter a crucial stage this weekend.

"The president is solidly behind his Central American envoy," Speakes said. "He thinks he's an excellent man that has served his country well in many capacities, and is doing so in this capacity."

In a letter to Reagan, Kemp charged that Habib's "confusing maneuvers and conflicting explanations potentially set the stage for a new Central American Yalta," a reference to the 1945 treaty among the United States, the Soviet Union and Great Britain that laid out terms of the postwar East-West balance in Europe.

Conservatives began to worry after Habib promised in a recent letter that U.S. aid to Nicaraguan antigovernment rebels, known as contras, or counterrevolutionaries, will end "on signature" of an acceptable Contadora pact, if it is honored by the leftist Sandinista government of Nicaragua. The conservatives have argued forcefully in recent days that Nicaragua cannot be trusted to honor any pact, and that contra aid must not cease.

"Ambassador Habib has become personally identified with a policy direction that cannot be sustained," wrote Kemp, who is regarded as a likely 1988 presidential candidate. "I urge you to recall Ambassador Habib and appoint a new negotiating team, led by someone who shares your goals."

Speakes read a careful statement that he said was "essentially what I've told you over the past 10 days."

The statement, which also was distributed at the State Department, said the United States would support "a comprehensive settlement in which all political and security commitments are simultaneously implemented, with concrete verification procedures to ensure compliance by all five parties" -- Nicaragua, Honduras, El Salvador, Costa Rica and Guatemala.

The term "comprehensive" means that the treaty must address all 21 objectives which include limiting military forces, implementing arms control, removing foreign troops and advisers, halting guerrilla subversion and promoting democratic institutions, the statement said.

"The United States would not consider itself bound to support an agreement which failed to achieve in a verifiable manner all the agreed objectives," it said.

A White House official said the statement was intended to "send a message" to Nicaragua, the negotiating nations and the U.S. right wing that all sides should remain calm. Habib retains the president's confidence, but the treaty has to meet U.S. objectives to be acceptable, and "we aren't going to leave the contras out on a limb" until it is, he said.

A delegation of Honduran congressmen said yesterday they are worried that the 15,000-plus contra troops might become homeless, armed brigands inside Honduras if cut off from U.S. aid. Honduran President Jose Azcona is expected to bring this issue up when he visits Reagan next week.