MOSCOW, Dec. 13—The Soviet press agency Tass accused the United States tonight of “gunboat diplomacy” and “gross blackmail” against India with its reported movement of an American naval squadron toward the Indian Ocean from the Gulf of Tonkin.

In a dispatch from the United Nations, Tass used the strongest language to date against Washington during the India‐Pakistan crisis in what seemed an effort to head off any possible American involvement in the conflict.

Moscow, which has directed its sharpest language against China in this crisis, has previously warned that its security interests are affected because the war is near its borders and has urged other powers not to interfere.

As the fighting in East Pakistan has approached a decisive stage and as world opinion, as registered in the General Assembly vote overwhelmingly favoring a cease‐fire, has swung against the Soviet and Indian positions, Western diplomats believe Moscow has become more sensitive about the actions of other powers.

Tonight's commentary, though less formal than an official Government statement issued through Tass, was the first specific attack since the earlier general warning issued through Tass.

Tass dismissed as a “pretext” the American explanation that the aircraft carrier Enterprise, several destroyers and other vessels were moving toward the Bay of Bengal to help evacuate Americans from East Pakistan.

‘Blackmail and Pressure’

“This gross blackmail and pressure are regarded in United Nations circles as a policy contradicting the United Nations Charter,” the Tass dispatch asserted.

In a related development, the Soviet press and radio carried a report today that the Soviet Union had formally protested to Pakistan over the stoning of wives and children of Soviet Embassy officials as they were boarding planes evacuating them from Islamabad on Sunday.

While sharpening criticism of both Washington and Rawalpindi, the Soviet Union stepped up its consultations with the Indian Government on the conduct of the war and related diplomatic tactics.

A special Indian emissary reportedly bringing a personal message from Prime Minister Indira Ghandi for Premier Aleksei N. Kosygin met with Foreign Ministry officials. Indian sources said he expected to see Mr. Kosygin tomorrow.