Two days of high-level talks on East Asia between the United States and the Soviet Union ended here today, with both sides maintaining strong differences over North Korea, Cambodia and other points of tension in the region.

Paul D. Wolfowitz, assistant secretary of state for East Asian and Pacific affairs and head of the three-person U.S. delegation, described the talks as "frank and businesslike."

Wolfowitz declined to discuss the substance of the talks, but a western diplomat familiar with them said that both sides started and concluded with strong differences of approach to North Korea and various other East Asian countries. "The positions of neither side changed," the source said.

Sources said both sides limited themselves to defining carefully outlined positions, which sets a tone for the Nov. 19-20 summit between President Reagan and Soviet leader Mikhail Gorbachev.

"A very important part of that agenda is specific regional problems, and in that sense our talks were important," Wolfowitz said.

The bilateral discussions, the first the two countries have held specifically on Asia in decades, are regarded by diplomats from some of the countries involved as a continuation of recent verbal Soviet-American cross fire over North Korea, Cambodia and the Pacific.

The U.S. administration has complained of a Soviet troop buildup along the Chinese border and heavy military support from Moscow in Vietnamese-occupied Cambodia and in North Korea. The Soviet Union, in turn, has charged the United States with preparing for aggression in Asia with a heightened naval and troop presence in the region.

The Soviet delegation, headed by Deputy Foreign Minister Mikhail Kapitsa, did not comment on the talks.

The bilateral meeting comes at a time when the Kremlin is showing increasing interest in Asia and regions bordering it. This spring, Gorbachev proposed an Asian collective security arrangment during the Moscow visit of Indian Prime Minister Rajiv Gandhi. In recent weeks, Vietnamese leader Le Duan, Cambodian Premier Hun Sen and Laotian Premier Kaysone Phomvihane have visited Moscow. In addition, Sino-Soviet and Sino-Japanese relations also have shown marked improvements this year, diplomats here said.

Westerners interpret Moscow's mounting interest in Asia as a signal of its concern about the Soviet Asian population and an attempt to strengthen its ties in areas with U.S. political interests.

Sources here describe the Soviet Union's military buildup in North Korea, for example, as a Kremlin attempt to counterbalance U.S. interests in South Korea. North Korea was a main focus of the bilateral talks, a western diplomat here said.

Wolfowitz left Moscow today for Tokyo, where he is expected to meet with Japanese officials.

The Asia talks are the fourth set of bilateral discussions Washington and Moscow have held this year. Earlier talks were held on the Middle East, Afghanistan and southern Africa.