Soviet miltary reservists along the Polish border in the strategic trans-Carpathian region have resumed intensive training for full mobilization at any time, reliable sources reported today.

The sources said the new phase of training began in late May and requires two days of military instruction and ideological indoctrination for all reservists up to age 35 to prepare them to defend "the socialist community" from an unnamed foreign enemy.

The reports, from unofficial sources who cannot be named, reached here as Soviet Foreign Minister Andrei Gromyko traveled to Warsaw to outline the Kremlin's views of the political crisis to the Stanislaw Kania leadership as Poland's Communist Party prepares for a crucial congress scheduled to begin July 14.

Informed Western sources said they credit the reports on the basis of certain changes -- which they refused to detail -- in miltary readiness in the region. But they said the reported preparations may be contingency moves that do not mean that use of military force by the Kremlin to stem the tide of Polish political reform is either imminent or inevitable.

it is said by the sources that instructions have once again been sent to all factories, farms, and enterprises in the mountainous region from the military command that it is their responsibility to see that a mobilization takes place without hitches. Last August, the sources have said, a sudden order to call the reserves to duty resulted in widespread chaos, desertions and the dismissal of numerous regional officials because of the unsatisfactory performance.

Now, the sources say, reservists are being called from individual factories and other places of work by the hundreds, given two days of indoctrination, and returned to civilian life. The sources say that the reserves have not specifically been told the new round of training is related to the Polish crisis, but that all assume this is the reason for it.

They further say that surveillance by Soviet secret police in the transCarpathia, in the western Ukraine, has increased substantially since May.The region is home to many who are of Czech, Hungarian and Polish descent.

As with the reported aftermath of last year's call-up, regional officials and directors of enterprises have been told to make sure they have a full work force on hand, to cancel vacations and business trips so that manpower remains at peak levels.

The reported start of the new training for reserves coincided with a stepped-up Soviet propaganda attack on alleged "counterrevolutionaries" in Poland in mid-May, which made clear the Kremlin's deep dissatisfaction with the way Kania was handling the challenge of reformers in the independent trade union movement Solidarity. Since then, Kania has withstood an attempt by hard-liners using a toughly worded Kremlin letter to oust him, and it is expected that he will be reelected party leader at the congress.

However, in trans-Carpathia, the sources say, reserves are being told that "a necessity has arisen in connection with complications in the international situation," and they must be ready to go to duty if an order comes to do so.

The Soviet state must guard against "counterrevolution" by an international conspiracy, which includes the United States, to undo the gains of socialism, the reserves reportedly are being told.

The new training effort appartently began about a month after chief Kremlin ideologue Milkhail Shulov flew to Warsaw for a day of talks with Kania and other Polish leaders. These apparently were marked by stiff disagreement as to how the Polish Communists should proceed in the face of the political reformers' pressure.

Reservists who were called up last August at a high point of Polish unrest are reliably reported to have been kept on duty until December, when they were finally returned to civilian life.

There are also reports of soliders from the region having been killed while serving on active duty. These reports, which like the reported new training effort cannot be independently verified, allege that some soldiers may have died in Poland. But it is unknown how, and their families, like the families of soldiers killed in the Afghan intervention, are simply being told they gave their lives in the service of the state.