Bangkok — With the prospect of a second Reagan term in sight, members of the six-nation Association of Southeast Asian Nations (ASEAN) are apparently increasing pressure on Washington to provide more aid to noncommunist guerrillas fighting for control of Kampuchea (Cambodia).
American aid to the anti-Vietnamese Coalition Government of Democratic Kampuchea (CGDK) is at the moment covert and - in theory at least - nonmilitary. ASEAN would like the aid to be overt and military.
Thus, while noncommunist CGDK factions recently received a substantial amount of military supplies from Singapore, the shipment was delayed for several months , partly in a Singaporean effort to make the US give aid itself.
There are signs that assistance from both ASEAN and the US may be increasing. A four-nation committee has reportedly been formed to coordinate the aid flow. The committee is believed to consist of representatives of Singapore, Thailand, and Malaysia - the three most active CGDK supporters in ASEAN - and the Central Intelligence Agency. ASEAN, with Singapore in the forefront, will probably keep up the pressure on Washington.
The latest Singaporean shipment consisted of about 3,000 AK-47s, the standard combat rifle of the communist world. Two thousand guns went to the Khmer People's National Liberation Front (KPNLF), the larger of the two noncommunist members of the coalition. The other 1,000 went to Price Norodom Sihanouk's fighting force. The shipment will give a substantial boost to the armed strength of the two groups. The KPNLF is usually estimated to have between 12,00 and 14, 000 men under arms, Sihanouk about half that.
The weapons were originally expected around May, but finally arrived in August. The Singaporeans attribute this delay to technical problems. ''It's hard to find that many AKs on the market these days,'' says one source conversant with the subject.
But Singapore seems to have found a source without too much difficulty: Poland, despite its close alliance with both Hanoi and Moscow, is believed to have sold some, perhaps all, the guns needed.
A Western observer in Bangkok attributes the delay to another reason. ''The Singaporeans want to see Washington put its money where its mouth is.''
American officials, when asked about US aid to the CGDK, stared absently at the ceiling and muttered vague denials. But in fact the US has been giving secret aid to noncommunist elements of the CGDK since it was created in 1982. It is thought to be $6 million or $7 million and to be channeled through the CIA.
Ostensibly it is intended for the coalition's external propaganda activities.
This allows US officials to say that any aid they give is nonlethal. As one put it, ''You can't kill people with money.''
In practice, an ASEAN official notes, few restrictions are put on the use of the aid. ''After all,'' the source says, ''GAO (the General Accounting Office) is not likely to come out here and audit the KPNLF.'' If the money were spent on guns, the source says, the US probably would not object, although it would probably prefer not to know.
ASEAN's maximum objective for a second Reagan term would seem to be a public commitment by the US to provide military aid to the KPNLF and Sihanouk. They will probably settle for less - covert military aid, for example. But at the very least they want to see the US show more vigorous support for Khmers.
The US maintains that it will follow ASEAN's lead. This line tends to irritate ASEAN. ''Frankly,'' a senior ASEAN source said, ''we would like to see Washington get out there and lead.''
China remains the largest supplier of arms to the CGDK. It has recently provided the noncommunist factions with antitank and antiaircraft weapons.