Militants occupying the U.S. Embassy here, apparently unable to agree among themselves, refused today to make arrangements for an American woman to visit her hostage son.

It is unclear whether the militants, who acknowledged that they were "confused" by the request, would eventually allow Barbara Timm, of Oak Creek, Wis., to visit marine Sgt. Kevin Hermening, 20, the youngest of 50 Americans who have been held hostage since Nov. 4.

The militants' failure to announce a decision on the visit came despite a public recommendation by Foreign Minister Sadegh Ghotbzadeh today that the visit be allowed as a "humanitarian gesture." Earlier, President Abol Hassan Bani-Sadr had given his support to Timm's effort.

[After a meeting of Iran's ruling Revolutionary Council Sunday night, it was announced that Bani-Sadr and Ghotbzadeh had written a joint letter asking that the militants allow Timm's visit. The militants would not acknowledge Monday that they had received the letter or indicate whether they would allow the meeting with Hermening.]

[Timm and her husband hand-carried the letter from the Foreign Ministry to the embassy Sunday night. She said she conferred with the militants for about an hour, but only discussed "things like motorcycles, traffic in Tehran, the mountains and the weather." She could not say how close she was to obtaining a meeting with her son and added that she would wait by her telephone for a call from the militants.]

[Meanwhile, Reuter reported that a member of the students' Central Council said the militants had agreed to let timm visit Hermening Monday afternoon.]

As indecision about whether to allow the first family visit to the hostages continued, there were these other developments:

Iran's oil minister, Ali Akbar Moinfar, said Iran would suspend oil shipments to Japan and seek new customers in Eastern Europe if Japan refused to pay higher prices demanded by Iran.

Tensions continued high on Iran's college cmpuses, where leftist and rightist students clashed the past two days.

Timm and her husband, Kenneth, appeared today to have run up against the realities of the U.S.-Iranian crisis and the repeated inability of Iran's officials to sway the militants holding the American Embassy.

Timm, optimistic on her arrival yesterday, found disappointment today when the captors appeared to renege on what she took to be an agreement in principle that she could see her son under "conditions" that were to be announced today.

But today the militants, apparently unable to agree on whether to set the precedent of allowing relatives to visit the hostages, failed to announce their terms as scheduled and indicated that they were undecided on letting Timm into the embassy at all.

Nor did she, her husband, who is Hermening's stepfather, and their lawyer, Cal McAfee of Norton, Va., appear to make any headway in efforts to win an audience with Ayatollah Ruhollah Khomeini or President Bani-Sadr to plead for Hermening's release.

At different times Sunday, the militants gave different answers when asked about their statement Saturday that they would announce their conditions for family visits by Sunday.

At one point, a spokesman for the militants said they had previously decided to refuse entry to all visitors who had not been invited by them.

Pressed as to whether this meant that the militants definitely would not allow the Timms to see Hermening, however, the spokesman said it did not.

He finally acknowledged, "We're confused."

Other spokesmen said only that the conditions would be announced later.

The principle of allowing families to visit their captive relatives was publicly supported again Sunday by Ghotbzadeh. He told a news conference that the militants would be acting like the jailers under the government of the deposed shah if they refused to let relatives see the hostages.

Ghotbzadeh said he believed that not only the Timms, but the families of other hostages, should be allowed into the occupied embassy "as a humanitarian gesture."

Sunday, Ghotbzadeh said he had made an unannounced "private visit" to Paris during the past few days to pick up some documents and "see some friends involved in the extradition of the ex-shah." He said no contact was made with any American officials or intermediaries and that there were currently "no negotiations under way" on resolving the hostage crisis.

In a separate news conference, Oil Minister Moinfar far warned that if Japan did not agree to pay Iran's new price of $35 a barrel, an increase of $2.50, sales of 530,000 barrels a day of Iranian oil to Japan would be stopped as of Monday.

The Japanese government has told its importers not to pay the new price. While it describes the decision as primarily economic, Japanese officials have acknowledged that one reason for the rejection is a desire not to undercut American pressure to free the hostages.

[In Washington, the White House praised Japan's decision. "We welcome the support of the Japanese and appreciate what they are trying to do," a spokesman said.]

Moinfar told reporters that if this situation continued, Iran would keep its oil in the ground and find better customers later. He said that Iran was discussing oil sales to Eastern European countries.

In another sign of a drift toward closer relations with the Soviet Union despite the ideological gulf between the two countries, Maj. Gen. Hadi Shadmehr, the chief of the Iranian military joint staffs, confirmed a "considerable increase on Soviet military maneuvers" but said that they were confined to the Soviet side of its border with Iran.

"It might be correct that these maneuvers are not without reason but they are not with the thought of committing aggression against Iran," Shadmehr said. "They are for the event of another force coming to Iran to act."