Three months after it suddenly was granted the fourth-largest arms package the United States will sell abroad this year, North Yemen is asking Washington to send senior U.S. military advisers to help reorganize its armed forces to use the equipment.

The appeal for a more direct American military role in the Arabian peninsula and Persian Gulf region is being delivered in Washington this week by Abdullah al-Asnaj, top political adviser to North Yemen's president, Ali Abdullah Salih.

Al-Asnaj called on Americans to "liberate themselves from the Vietnam complex" by actively defending "certain political values" in the region and offered high praise in an interview here for President Carter's decision last March to rush $390 million in sophisticated weaponry to North Yemen during a brief border war with South Yemen's Marxist government.

The praise, and a plea for more direct help, also was contained in a letter al-Asnaj handed to Secretary of State Cyrus R. Vance Monday during a meeting. The Yemeni official, who was until recently foreign minister, met with members of Congress yesterday.

Carter employed the first waiver ever used to speed a scheduled arms delivery around congressional review for the Yemen arms package, which administration officials said was intended "to draw the line" against Soviet-backed "destabilization" efforts against governments friendly to the West and to Saudi Arabia in particular.

But al-Asnaj reported that the 30,000-man North Yemeni army, which largely has been trained and equipped by the Soviet Union over the past decade, was having trouble converting to U.S. materiel and methods, and would benefit from "a reorganization program" that would be directed by U.S. officers stationed in North Yemen.

The 30 to 50 U.S. military instructors training the North Yemenis on the new equipment have been rotating from the United States for short stays. Members of a military planning and command structure team headed by Maj. Gen. Richard Lawrence, stationed temporarily in Saudi Arabia, also have visited North Yemen to survey that country's defense needs.

Al-Asnaj said North Yemen would welcome a similar planning mission, and predicted that permanently stationing senior American officers in the area would not draw criticism from other Arab countries.

In a clear reference to the Soviet advisers in South Yemen, al-Asnaj said of the other Arab countries: "Have they objected to others being present in the area? It is how you present your case. Allow these states to invite you, and eventually they will invite you. . . . The American role should be to remind those that are interfering in the region that they should refrain from doing so."

Al-Asnaj's appeal for a more direct military relationship with Washington appeared calculated in part to put South Yemen on notice that future fighting could involve direct American opposition, although he stressed in the interview that he "was not trying to drag Americans into anything."

His comments to congressional sources yesterday also indicated irritation with slow deliveries of the U.S. arms through Saudi Arabia. The Saudis are paying for the arms package and insist on American military help for North Yemen being channeled through Saudi Arabia.

North Yemen privately has sought a direct military supply relationship with Washington since 1975, when discussions on an arms deal began. Al-Asnaj said in the interview that he welcomed direct economic and cultural ties with the United States, but he emphasized that any increased U.S. presence in North Yemen should be made in the context of the trilateral military arrangement.

North Yemen has received most of the $390 million arms package, which includes a squadron of F5E jet fighters, 64 M60 tanks, 100 armored personnel carriers and Vulcan antiaircraft guns.