Russian forces moved to high ground overlooking the major roads into Grozny today and cut the city's main road link to the west, putting a military stranglehold on the capital of rebellious Chechnya.

The positions occupied by Russian forces suggested they are at least planning a siege to cut off the Chechen leadership from the rest of the region. But Russian officers in recent days also have expressed determination to recapture the city, from which their forces were expelled near the end of a two-year war in 1996 that left Chechnya effectively independent.

Prime Minister Vladimir Putin has said Russia's 3 1/2-week-old ground offensive is designed to eliminate terrorists accused of planting bombs at apartment buildings in Moscow and other Russian cities last month, and also to put a halt to incursions by separatist Islamic guerrillas into neighboring Dagestan. With each passing day, however, the war aim has seemed more and more indistinguishable from conquest of the entire region and its return to Russian rule.

Today, the Russians took control of the border crossing on the road between Grozny and Nazran, the largest city in the neighboring region of Ingushetia. The road was the primary route out of Chechnya for more than 170,000 refugees who have fled the air and ground offensive. Hundreds of refugees were stranded today on the Chechen side of the frontier, according to Russian television news reports.

Russia already dominates the northern third of Chechnya, and has systematically crept closer and closer to Grozny while carrying out air and artillery strikes there and at other population centers. Grozny is without water, electricity and natural gas. It is a desolate city of fearful, impoverished residents, and an armed camp for Chechen fighters who are dug in and awaiting a Russian ground attack.

The attacks on civilian areas have brought Russia international criticism. The United States and the European Union have called for restraint and talks to end the conflict.

Russian officials lashed out today at calls by Deputy Secretary of State Strobe Talbott for a political settlement. Parliament speaker Gennady Seleznev, a member of the Communist Party, said neither the United States nor NATO has "the moral right to tell Russia how to settle the acute conflict."

NATO "did not sit down for a political settlement of the Yugoslav situation," he added, reflecting widespread opinion here that NATO's bombing campaign during the war for Kosovo makes Western criticism hypocritical.

Gen. Leonid Ivashov, who heads the Defense Ministry's international affairs department, said negotiations with "terrorists" are out of the question. "The terrorists must either lay down their arms or be liquidated," he told reporters.

The Russians seized the border crossing on the Nazran road from Ingush forces, which had permitted a free flow of Chechen refugees into Ingushetia. Gen. Vladimir Shamanov, commander of the western front, explained the seizure by saying that the Ingush had failed to register incoming refugees, and had not stopped trafficking in stolen cars. "This was not done," he said heatedly.

Besides control of a possible infiltration route, the blockade takes away the main route used by foreign journalists to enter Chechnya and report first-hand on the conflict.

Three days ago, the Russians effectively took the first step at reducing the flow of information out of Chechnya by arresting Mairbek Vachagayev, the Chechen representative and main spokesman in Moscow.

He was detained Wednesday for illegal possession of arms, and the Russians say they will put him on trial.

The sealing of the border coincided with moves by Russian troops along the low Sunzhensky mountain range north of the Nazran road and west of Grozny. The range commands a view of a string of towns leading to the capital and thrusts to within four miles of the city center.

Russian officials said their troops ran into occasional resistance from Chechen forces during the advance. Fighting also took place at the village of Sadovoye, less than 10 miles northwest of Grozny.

Russian troops appear to be moving on Grozny from at least two sides: from the west and from the northwest, along a ridge just south of the Terek River. Russian planes and artillery were also assaulting Chechen lines of defense north of Grozny near the village of Tolstoy-Yurt.

Russian officials continued, meanwhile, to give differing explanations for the blast in Grozny that killed scores of civilians Thursday. Gen. Valery Manilov, the deputy army chief of staff, said that as a result of a Russian "special operation," two gangs of Chechen "bandits" were induced to open fire on one another at the central market. A stray bullet hit a nearby arms cache, where among other things, rockets were hidden. The shot "caused a powerful explosion," he said.

But Izvestia, the first Russian newspaper to take issue with official accounts since the war began, said the Russians actually fired a surface-to-surface missile from North Ossetia, another neighboring region. The targets were government offices, where Chechen military commanders were thought to be meeting, it said.

Among the participants, according to Izvestia, was Shamil Basayev, who led a rebel incursion last August into Dagestan. Russia considers him the mastermind of Chechen-based terrorism.