The Taliban have also not heeded appeals to return to the negotiating table and continue long-stalled peace talks with the Afghan government.
India has been supporting a national peace and reconciliation process which is Afghan-led, Afghan-owned and Afghan-controlled.
Taliban claims to control 85 per cent of Afghanistan; President admits to difficulties in handling situation
Taliban said fighters had seized the border town of Islam Qala -- completing an arc of territory from the Iranian border to the frontier with China.
This week more than 1,000 Afghan troops fled into Tajikistan after a blistering offensive by the insurgents in the north of Afghanistan.
Biden also dismissed reports that the Taliban would take over the country soon after the withdrawal of the American troops from Afghanistan.
The surge of fighting, and the sudden news of peace talks in Tehran, come at a critical time for the war-battered country.