The D.C. zoning commission and the State Department clashed early this week over a Japanese government request for permission to expand its Massachusetts Avenue chancery.

The request came as the city prepares to consider regulations to implement the new Foreign Missions Act passed by Congress last year. Because the law requires the city to change the way it handles zoning for diplomatic missions, requests such as the Japanese petition have been thrown into limbo until the regulations are issued.

City and State Department staff members have drafted a set of regulations, but the first public hearings are not scheduled until April 11.

The commission refused to act on the Japanese request--despite the State Department's urging--in effect denying it. At the hearing Monday, State asked the commission to adopt the regulations on a 120-day emergency basis, an action that would have enabled the city to consider the Japanese construction plans right away.

Observing sharply that "there is no emergency," outgoing commission chairman Walter B. Lewis said the Japanese government had applied for city approval of its expansion plan under the old law. "If Congress had not changed the law, it the Japanese request would have been" acted upon by now.

The law "was changed at the suggestion, and indeed stong support, of the State Department . . . and now . . . it says, in addition to that, there's an emergency. Now, they can either have their cake or eat it. They can't have both."

To enact emergency regulations, the zoning commission must be convinced that "the public peace, health, safety and welfare will be adversely affected without emergency rules," said Cecil B. Tucker, secretary to the commission. The State Department's request "failed to meet that test."

Until the city approves regulations to implement the new federal legislation, zoning authorities cannot accept or consider applications from foreign governments, according to Steven Sher, executive director of the commission.

The Foreign Missions Act, which became law Oct. 1, is a wide-ranging law that, among other things, requires foreign governments and international organizations to obtain State Department permission before buying or selling property.

In addition, the law widens the parts of the District where chanceries can be located.

The purpose is to give the U.S. government leverage for demanding better treatment for American diplomats abroad, State Department officials said. Embassies of friendly countries are expected to get the permission routinely, while those of nations dealing harshly with our diplomats will encounter stricter applications of the rule in Washington.

The city has not been enthusiastic about the act, which many of its officials regard as an unnecessary restriction on Home Rule.

To critics of the new law, the State Department's appeal on behalf of the Japanese government appeared suspiciously like a maneuver to prod the District government into moving faster to approve implementing regulations.

A spokesman in the office of Sen. Charles McC. Mathias Jr. (R-Md.) said that before passage of the Foreign Missions Act, the senator's staff was told "the Japanese were in no particular hurry to expand their chancery . They had been informed that their application would be returned and they would have to wait."

Mathias was active in an effort to prevent the State Department from taking away city authority over the location of foreign embassies and chanceries. Early drafts of the act would have stripped the city of most of its powers, District officials said. Under the bill that became law, city zoning authorities will continue to review most applications for chancery moves.

The Japanese now say they had no idea they would have to wait so long for the new law to be implemented. A spokesman said the embassy is in danger of losing money its government has appropriated for the project unless the funds are used soon.

James Wood of the State Department's Office of Foreign Missions said the department "made an effort to accommodate" Japanese diplomats because "this thing [drafting of city zoning changes] had been going on for months . . . and this seemed to be a vehicle. . . ."

"Our biggest and most modern embassy abroad is in Japan," said Wood. "The Japanese government was very helpful to the U.S. when we had similar [budget] problems."

He added, however, that his office did not intend to "put pressure" on the city government.

Three days after the zoning commission meeting, the National Capital Planning Commission (NCPC), which is responsible for protecting federal interests in the District, postponed a vote to approve circulation of new rules that, if approved, would bring the NCPC's comprehensive plan for the city into conformity with the federal law. Commission members said they did not receive copies of the proposed rules until late afternoon before their meeting the following morning.

NCPC must circulate proposed changes in its city plan to city agencies and community groups before members vote on adoption.

The proposed changes were "put on the agenda this week, but we have been working on them since the Foreign Missions Act" went into effect last October, said Reginald W. Griffith, NCPC executive director. This week's agenda item on the rules changes has "no connection whatsoever" with the zoning commission's actions earlier in the week, said Reginald W. Griffith, NCPC executive director.

At its meeting, the city zoning commission scheduled public hearings on the changes for April 11 and 14. The process of changing the city regulations could be completed by mid-summer if no complications are encountered, said Sher.