Deputy Secretary of State Warren M. Christopher said yesterday that the Soviet Union is "pouring in additional troops" in Afghanistan and now has "well over 100,000 probably over 110,000 men there."

Previous estimates were that the Soviet Union had sent in 80,000 or 85,000 troops to try to subdue resistance to its four-month-old invasion. Another 20,000 to 30,000 troops had been reported massed along the border between the two countries.

Christopher said that he had just read an analysis comparing the difficulties the Soviet Union is having in Afghanistan with those the United States had in Vietnam.

Although the two situations are "obviously not . . . completely parallel," the Soviet Union "is having a great deal of Difficulty in Afghanistan," Christopher said on "Issues and Answers" (ABC, WJLA).

"Their generals are asking for more troops," Christopher said. "They're having a great deal of difficulty using the Afghan army . . . I would say that's the main preoccupation of the Soviets at the present time."

Asked whether the Soviets' troubles in Afghanistan would be good or bad for the United States in the long run, Christopher seemed to suggest that there had been a victory for administration policy. He said:

"Our whole policy with respect to that invasion has been, first, to make them pay a heavy cost for that, and, second, to deter them from taking comparable action in the future.

"And I think they are being shown that when they try to go in and take over an independent country, shoot up its mosques, and execute a number of its people, that they can't easily subjugate that kind of country.

"The Afghan people are brave and determined people, and they're giving the Soviets a great deal of difficulty. If I were sitting in the Soviet Union I would not regard that as the kind of event that would encourage me to repeat it."

By contrast, the administration's response to the invasion drew sharp criticism from Sen. Henry M. Jackson (D.-Wash.), who recalled on "Meet the Press" (NBC, WRC) that President Carter had termed the invasion the greatest crisis since World War II.

Jackson termed it "criminal" that the United States still hasn't established tactical air and supply bases in countries willing to have them, particularly Egypt, Oman and Somalia.

He also said that in a phone conversation a few days ago, Egyptian President Anwar Sadat expressed a desire to join in a Middle Eastern "security arrangement in which the United States would be the ultimate guarantor."

As proposed by Jackson, the arrangement would come into play in event of a coup or attempted coup. At the call of a threatened government, other Islamic states would provide help, including ground troops, while the United States would provide air and supply support but not troops.

The prospective members of the pact listed by Jackson included Egypt, Morocco, Oman, Saudi Arabia, Somalia, Sudan and Tunisia.

Jackson said that "to restore American credibility in the diplomatic and negotiating process," he will lead a fight in the Senate for the United States to build a large stragetic oil reserve. Currently, 92 million barrels are in the reserve, which is intended to insulate the country from a sudden cutoff of the imported oil accounting for half of U.S. consumption.

Jackson said he understood that the reserve is a sensitive issue with Saudi Arabia, which wants nothing done until June or so in order to give it time to work out the issue with other oil-exporting nation. "I want to cooperate, but the answer must come not later than that time frame," Jackson said.

Jackson and Sen. Frank Church (D-Idaho), chairman of the Senate Foreign Relations Committee, appearing on "Face the Nation" (Cbs, WDVM), both rejected suggestions that Israel could be "pressured" into accepting a Middle East "solution" that imperils its vital interests.

If a sovereign Palestinian state were to be set up on the West Bank, it could invite the Russians in, and that, Jackson said, "would be the end of Israel."