WASHINGTON — Soviet President Mikhail Gorbachev agreed to President Bush's urgent appeal to speed up efforts to complete a long-range strategic arms agreement and accepted an invitation to send a delegation to Washington this week to pursue the negotiations.White House press secretary Marlin Fitzwater said yesterday that Soviet Ambassador Viktor Komplektov conveyed to national security adviser Brent Scowcroft Mr. Gorbachev's response to Mr. Bush's appeal. Mr. Fitzwater said Foreign Minister Alexander Bessmertnykh will arrive tomorrow evening and will meet with Secretary of State James Baker III on Thursday and Friday. Bush had asked Gorbachev over the weekend to step up the stalled negotiations in hopes of winding up an arms pact by the end of the month. Bush stressed that START, the strategic treaty to cut Soviet and US nuclear long-range missile arsenals by 30 percent, must be completed before a Moscow summit can be held. The two leaders are planning to meet at the conclusion of the Economic Summit in London on July 17. While Bush has accelerated efforts to break the deadlock on the remaining technical issues holding up an arms accord, the Soviet leader appeared to be impeded by Soviet military leaders who have been hesitant to go the next step in arms control. Gorbachev has been anxious to hold a summit meeting, and administration officials still held out the possibility one could take place in late July. The START treaty has been in negotiation for nine years. While some 90 percent of the agreement has been ironed out, the remaining obstacles center on verification procedures, ways to limit data broadcast from missile test flights, and formulas to reduce the number of warheads on missiles that will remain.