Prime Ministers Atal Behari Vajpayee and Nawaz Sharif received letters ``urging restraint and ... a resumption of the Lahore dialogue that is the foundation of the engagement between the two sides,''spokesman David Leavy said yesterday.

The letter said, ``It's our best judgment that their own security is not enhanced by having nuclear weapons,''he said.

``In fact, the presence of nuclear weapons on the subcontinent raises the possibility of an arms race that's in no one's interest,''Leavy added.

``We'll continue to make clear to both sides that it's our hope that they can engage directly on adhering or eventually ratifying the CTBT, the Comprehensive Test Ban Treaty, which is so much in our own interests and in the interest of both sides,''the White House spokesman said.

On Sunday, Vajpayee ruled out any resumptionof a dialogue until Islamabad ceased sponsoring terrorism in Kashmir. India would take all measures necessary to defend itself, he said on Independence Day.

Pakistani Prime Minister Nawaz Sharif on Saturday used the country's 52nd independence anniversary to warn India that any future military aggression would be met with ``a telling response''.

Meanwhile, Senate majority leader Trent Lott has assured the Indian community in the US that he will wholeheartedly support moves to lift the sanctions imposed against India, after its nuclear tests last year.

The Republican Senator assured a delegation of the American Association of Physicians of Indian Origin (AAPI) in Mississippi on Tuesday that he would make every effort to see that the sanctions against India were withdrawn, an AAPI release said here on Wednesday.

He said he realised the importance of Indo-American relations and that these had ``cooled due to these sanctions'', the release added.

Lott recalled the cordial relations he had with theIndian community in Mississippi and praised the role it was playing in vital areas of the state and the country, especially in the fields of medicine, science, engineering and business.

Lott gave his views on the sanctions when the issue was raised by the delegation comprising, among others, AAPI president Dr Satya Ahuja, the body's Legislative Affairs Committee's co-chair Dr Sampat Shivangi and Dr Surinder Purohit, the release said.

Lott also promised to help meet the health concerns of the Indian community.