WARSAW, SEPT. 26 -- Vice President George Bush forcefully told Polish communist leader Gen. Wojciech Jaruzelski today that Poland must carry out political reforms sought by the banned Solidarity trade union if it is to expect increased economic assistance from the United States, according to U.S. officials.

Bush delivered the message as he opened a four-day visit here that quickly blended campaign-style outdoor appearances with tough private exchanges and unexpected conflicts over his activities.

Plunging into a round of public ceremonies in front of friendly crowds, Bush was filmed by a video crew hired by his presidential campaign as he greeted Poles at monuments to Poland's unknown soldier and the World War II resistance fighters of the Warsaw ghetto.

At the same time, Bush received a cool, formal reception from Jaruzelski's government, which gave a minimum of public display and publicity to the visit and published sharp assessments of U.S.-Polish relations in the state-run media.

"Poland will not forget the injustices suffered from the hands of the United States," said an official commentary of the state news service PAP. It added, "Time has shown that the anti-Polish American policy of sanctions and restrictions proved to be futile for Washington."

The day's varying events underscored the different agendas of the vice president's visit. Bush came to Poland in part to bolster his campaign for the presidency by highlighting his role and experience in foreign policy. At the same time, the visit comes as the Reagan administration has reached a difficult juncture in its relations with Warsaw after a year of slow improvement.

Completing a process of restoring formal relations, Bush and Jaruzelski today reached final agreement on exchanging ambassadors after a break of almost five years. But officials said Bush had the mission of driving home the message here that further substantive improvement in U.S.-Polish relations would not be possible without steps of political liberalization that Jaruzelski has refused to take.

One senior U.S. official said the Bush visit was motivated by the politics of his presidential quest but was also "heaven-sent in policy terms" because of the need to place new pressure on Warsaw.

Polish authorities seem supportive of Bush's political priorities here but also anxious to insist on a quicker restoration of U.S.-Polish economic exchanges. In particular, the Poles want U.S. support for critically needed assistance from the International Monetary Fund, the World Bank and western creditor governments.

Officials confirmed today that, in a meeting with the vice president, Jaruzelski expressed "resentment" over U.S. sanctions imposed in 1981 in response to the declaration of martial law and the suppression of Solidarity. The sanctions were lifted last February, but Poland has continued to suffer from a drought of western credit and technology.

Responding to the Polish concerns, Bush today told Jaruzelski that Solidarity enjoys wide support in the United States and that no further economic aid concessions will be forthcoming unless Poland makes new internal reforms, according to officials.

A senior U.S. official told reporters that a resolution of these conflicts is not expected during Bush's visit here. In their opening talks, Bush told Jaruzelski that he wanted to be frank with the Polish leader without making him angry, and Jaruzelski said he hoped the vice president would leave smiling, officials said.

In a conciliatory arrival statement, Bush said this morning that "I want to make clear that our intention is not to disrupt or divide, nor is it to interfere."

As the two leaders talked, U.S. and Polish officials were locked in a day-long dispute over political symbolism as the Polish government sought to block a planned Bush visit to a private farm near Warsaw. U.S. officials said that the Poles were concerned a private farmer would make politically embarassing statements against Jaruzelski's government and that such an appearance would draw unwanted attention to Poland's large private farm economy.

The dispute appeared to be settled late today only after Bush agreed to visit a farm selected by the communist authorities in addition to the farm previously selected by U.S. officials.

Before Bush's arrival here, his aides had said he would have unfettered contact with differing segments of Polish society. Bush had already planned to meet with Solidarity leader Lech Walesa on Sunday and visit the grave of the movement's martyr, priest Jerzy Popieluszko.

Today, Bush conferred with Polish Roman Catholic primate Cardinal Jozef Glemp and met with a group of moderate Catholic intellectuals, including several former Solidarity advisers, as well as members of an advisory council to Jaruzelski.

As he traveled around the city, Bush responded enthusiastically to the friendly crowds, some of whom carried welcoming banners bearing official communist slogans. Authorities did not publicize Bush's schedule, and there was no sign in the crowds today of the Solidarity activists who normally appear at open public events.

U.S. officials here conceded today that they may have caused unneeded offense to a prominent opposition leader by withdrawing his invitation to the dinner planned tomorrow night for Bush, Walesa and other Solidarity activists. Jacek Czaputowicz, leader of an organization called Freedom and Peace that is active in promoting conscientious objection and environmental protests among youth, was originally asked to the dinner but later uninvited because of concerns about tensions between him and Walesa, officials said.

{"There is a very strong attack on us from the side of the authorities, and the meeting with the vice president could have strengthened our position," Czaputowicz told The Associated Press. "It is difficult for us because three of our people are in jail" for refusing military service.}