Israeli Prime Minister Menachem Begin, carrying his own secret peace proposals, arrived here yesterday for White House talks which may determine the future of President Carter's Middle East diplomacy.

Stepping from an Air Force plane Carter sent to bring him from New York, Begin expressed hope that the discussions will lead to progress toward "real peace" in the region. He did not disclose any details of his proposals, which Israeli officials describe as "a comprehensive plan for settlement in the Mideast."

High administration officials profess to be in the dark about the heralded proposals, which were approved by the Israeli cabinet a week ago with a strict injunction from Begin that they be kept secret until presented to Carter.

The chairman of the House International Relations subcommittee on the Middle East, after a 10-day trip to the region, called yesterday for Israeli "flexibility" in peace negotiations. Rep. Lee Hamilton (D-Ind.) reported that chairman Yasser Arafat of the Palestine Liberation Organization (PLO). in a conversation in Cairo last week, seemed reconciled to living in peace with Israel in a Palestinian mini-state of even very small size.

Israeli officials said Begin will make public his "great outline" and "philosophy" at a press conference Wednesday, but they did not promise that the all-important details will be revealed.

A crucial question is the new Israeli government's view on withdrawing from all or part of the West Bank of the Jordan River, which Israel captured in the 1967 war and has occupied ever since. Shortly after the election that brought him to power in mid-May. Begin called the West Bank "our land" and "liberated territories" and said withdrawal was inconceivable.

Another highly important issue is the question of a Palestinian entity or homeland on part of the West Bank territory now held by Israel. Begin said in New York over the weekend that creation of a Palestinian state would place Israel in "mortal danger" and "can never come into being." However, U.S. officials plan to explore with him the possibility of a Palestinian entity closely linked to Jordan.

Along with Arab acceptance of a peace agreement and of extensive Israeli relations. Israel's withdrawal from nearly all the territory it occupied in the 1967 war and creation of a mini-state for the Palestinians are fundamental points of the comprehensive peace agreement Carter has outlined in recent months. If Begin remains unyielding on major points, Carter will have to abandon or water down his Middle East initiative or face a showdown with Israel.

U.S. officials have expressed optimism that Begin will prove more pragmatic than some of his early statements indicated. They hope he can clear up the seeming contradiction between his willingness to negotiate on all issues and his unwillingness to envision withdrawal from the West Bank and creation of a Palestinian state.

There are strong indications that both U.S. and Israeli officials are anxious to avoid the appearance of a head-on clash at this stage, no matter what the differences in substance.

According to Rep. Hamilton, who led a four-member delegation to Israel, Syria, Jordan and Egypt, the gap in ideas between Jews and Arabs on a peace agreement is still "tremendous," although all concerned strongly desire a Geneva conference as a stop toward a regional settlement.

Along with Rep. David Obey (D-Wis.). Hamilton spent two hours with PLO chairman Arafat. Describing his statements as "circuitous" rather than explicit. Hamilton said Arafat indicated in a variety of ways that he is prepared to accept Israel in the context of a Middle East agreement.

"My impression is that if a Palestinian state, even a very small one, were made available he (Arafat) would find that satisfactory and would devote himself to the development of that state," Hamilton quoted Arafat as saying. "Give me a piece of land and I will be satisfied with it." However, he said Arafat did not explicitly pledge to forego military action against Israel.

Hamilton said Arafat gave the impression that the PLO is "open" on the question of confederation between Jordan and a future Palestinian state. Egyptian President Anwar Sadat has called for such a link to be arranged even before the convening of a Geneva conference.

The congressman said he believes the United States should initiate discussions with the PLO as well as other Palestinian leaders in an effort to arrange a peace agreement. The United States has so far refused to recognize the PLO, in part because of a written pledge given to Israel in 1975 by then Secretary of State Henry A. Kissinger.

Begin will be welcomed officially by Carter in a White House ceremony this morning. The two will immediately begin their talks, which are scheduled to end Wednesday.