House Speaker Jim Wright (D-Tex.) charged yesterday that President Reagan is undermining their joint Central American peace initiative by criticizing the efforts of regional leaders and emphasizing his determination to seek $270 million in aid for Nicaragua's contras.

"The truth is that I've had a very difficult time getting any cooperation from the White House or State Department or abating their active opposition to the negotiations in the region," Wright said in an interview.

Wright refused to say that he regards the administration's actions as an abrogation of the joint initiative he and Reagan announced Aug. 5. But a source familiar with his thinking said Wright had become very aggravated by what he regards as the administration's tilt toward negativism and "is trying to hold the president's feet to the fire" in terms of seeking a peaceful resolution to Nicaragua's conflicts with its neighbors.

Wright was described as greatly angered by the administration's attempts to get him to cancel or play down the importance of his invitation for a meeting next Tuesday between members of Congress and Costa Rican President Oscar Arias, author of a separate peace plan adopted by five Central American presidents Aug. 7 in response to the Wright-Reagan initiative.

According to the source, Wright's invitation to Arias initially was seconded enthusiastically by White House chief of staff Howard H. Baker Jr. However, the source said, a few days later, the administration reversed itself. Wright acceded to a request not to make the event a formal joint session of Congress. The administration then tried unsuccessfully to persuade Wright either to call off plans for an informal meeting, which is to include an address by Arias, or to move it from the House chamber to a location away from the Capitol, the source said.

Wright cited as "a very strained and psychologically bad way of complying with our agreement" Secretary of State George P. Shultz's announcement to Congress last week that the administration will ask for $270 million in new military aid for the contras after Sept. 30. He also criticized Reagan's statement, in last Saturday's radio address, that the Arias plan lacks proper safeguards for ensuring democracy in Nicaragua and cutting that country's ties with communist countries.

Wright said he become involved in the bipartisan plan only after lengthy talks with Baker, Shultz and Reagan's national security adviser, Frank C. Carlucci, convinced him that the administration had recognized that it has little chance of persuading Congress to renew contra aid and was sincere in shifting its emphasis to seeking a negotiated settlement.

"Before we made our announcement on Aug. 5, I had an agreement with Mr. Reagan that we would set forth our general ideas and that if the Central Americans were to adopt a similar approach -- we never expected it to be identical -- we would give it an opportunity," he said. "Our agreement was that we would talk about peace and we would not talk about military matters or weapons or aid to the contras while the peace process was going on."

However, Wright continued, almost immediately after Costa Rica, Nicaragua, El Salvador, Honduras and Guatemala accepted the Arias plan in a Guatemala City meeting and set Nov. 7 as the deadline for reaching an agreement, the administration began to take an increasingly hostile attitude toward the process.

"Our initative was superseded by the Guatemala plan," he said. "I embraced it, and I still do. I think it has a good chance. But the administration seems to have forgotten our agreement to talk about peace."

In a related development, House Minority Leader Robert H. Michel (R-Ill.) told reporters yesterday that he intends this week to seek $8 million in continued aid for the contras as part of a short-term overall spending bill. Michel said that when he told Reagan of his plans, the president replied: "You know that I have made no bones about my continuing support for the freedom fighters."

Wright, asked about Michel's plan, said he understood that Michel is seeking a temporary continuance of humanitarian aid and added: "I haven't discussed it with Bob, yet, so I'm not sure what's in his mind. But I believe it can be worked out without pyrotechnics."