Iraqi Vice President Saddam Hussein said yesterday that Baghdad is ready to establish direct diplomatic relations with the United States if that is found to be in the best interests of the Arab world.

Hussein's statement, made in a magazine inter view and relayed by the official Iraqi news agency, was taken more as a general expression of principle than an overture for swift reestablishment of relations with Washington.

Iraq severed its ties with the United States in 1967, at the time of the six-day Middle East war. It consistently has maintained a hard-line policy toward Iraq and the Soviet Union and the renewal of fight against the Camp David accords.

There have been several periods during the last few years, however, during which the Iraqi government seemed interested in ending the estrangement But none came to anything concrete and U.S. diplomats have grown skeptical about general expressions of good will such as that made by Hussein.

The comments yesterday neverthelss evoked interest in light of recent strains in relations between Iraq and the Soviet Union and the renewal of friendly relations with Syria after Baghdad's years as odd man out in the Arab world.

Hussein's remarks coincided with the second day of a visit to Israel by U.S. Defense Secretary Harold Brown, who took a half-day tour of the Israeli-occupied West Bank and Golan Heights. The inspection was designed to demonstrate how narrow Israel is and why Israel feels its military presence on the West Bank must remain.

Brown was told Tuesday that Israel's arms needs might drop as much as 20 percent in some categories through the mid-1980s. This was depicted as a reflection of reassessed defense needs in the hope of a peace treaty with Egypt.

American Defense Department officials stressed, however, that the Israeli assessment has not been completed and that the estimates of reduced needs were only preliminary.

U.S. military aid to lsrael has been about $1 billion annually in recent years.

In Lebanon, Christian militias and Syrian troops exchanged artillery fire in Beirut and the surrounding mountains, Christian spokesmen reported. Four persons were killed and 10 others wounded, they said.

The Syrians form the bulk of a 30,000 man Arab League peacekeeping army dispatched in 1976 to halt the Lebanese civil war.