The State Department has adopted a new policy on human rights abroad that emphasizes opposition to abuses in the Soviet bloc but does not ignore abuses by friendly nations, sources said yesterday.

The policy, set out in a memorandum Oct. 27 by Deputy Secretary of State William P. Clark and Undersecretary of State Richard T. Kennedy, recognizes that a viable effort "means trouble" because it requires "hard choices which may adversely affect certain bilateral relations."

The memorandum, published yesterday in The New York Times, said:

" . . . At the very least, we will have to speak honestly about our friends' human rights violations and justify any decision wherein other considerations economic, military etc. are determinative. There is no escaping this without destroying the credibility of our policy, for otherwise we would be simply coddling friends and criticizing foes."

The memorandum said that "while we need a military response to the Soviets to reassure our friends and allies, we also need an ideological response."

That is to be accomplished, the document said, by acting to defend "political liberty" and "identifying its enemies" in order to demonstrate the difference between East and West, which is described as "the crucial political distinction of our time."

Among practical applications cited in the memo are abstaining or voting against loans to friendly countries in international banking institutions "if their conduct merits it" and withholding export licenses for police equipment "in questionable cases."

It is uncertain whether the new policy will affect earlier decisions, which drew congressional criticism, to reverse the Carter administration policy of opposing loans for Argentina, Chile, Uruguay and Paraguay. The Reagan administration reportedly is also preparing to vote for a loan to Guatemala. Lawmakers also criticized a reported decision to sell police equipment to South Korea.

The newly established policy is closely associated with the nomination of Elliot Abrams to be assistant secretary of state for human rights. The post has been vacant because the nomination of Ernest W. Lefever was withdrawn in June under heavy congressional fire.

When Abrams' nomination was announced by the White House Oct. 30, a statement by President Reagan said "the promotion of liberty has always been a central element of our nation's foreign policy. . . . We will encourage those who seek freedom, not the least by telling the simple truth about their efforts and the efforts of those who seek to oppress them."

Deputy Assistant Secretary of State Peter Constable cited U.S. concern about "liberty" in testimony about human rights in the Middle East before two House Foreign Affairs subcommittees yesterday.

Constable cited the peace-making mission to Lebanon by Special Ambassador Philip C. Habib and U.S. aid to Afghan refugees among U.S. human rights efforts in the region. He strongly criticized the Iranian regime of Ayatollah Ruhollah Khomeini, the Soviet-sponsored Afghan regime and announced absention on human rights grounds on World Bank loans to South Yemen, a Soviet-backed regime.

Constable took a hopeful view of the martial-law regime of Gen. Mohammed Zia ul-Haq in Pakistan, referring to "alternate periods" of increased and eased restrictions on political activity there. A new large-scale U.S. aid program to Pakistan was justified as required in the face of a Soviet military threat from neighboring Afghanistan.

Rep. Lee H. Hamilton (D-Ind.) criticized Constable for failing to mention "2,000 people thrown into jail in Egypt" despite U.S. leverage there.