Bolton said the US has been very clear to Pakistan on ending support to terrorist safe havens.
"We have been very clear on that score... And, we are continuing to be in discussions we are going to have with the Pakistanis," he said.
Earlier, the White House and Secretary of State Mike Pompeo asked Pakistan to end its support to terrorist safe havens inside the country.
"We stand with #India as it confronts terrorism. Pakistan must not provide safe haven for terrorists to threaten international security," Pompeo said on Twitter.
The U.S. condemns yesterday’s horrific terror attack on Indian security forces. My thoughts and prayers are with the victims and their families. We stand with #India as it confronts terrorism. Pakistan must not provide safe haven for terrorists to threaten international security.
In a stern message to Pakistan, the White House asked Islamabad to "immediately end" its "support" to all terror groups and not to provide "safe haven" to them, as the US condemned the brutal Pulwama terror attack claimed the lives of at least 40 CRPF soldiers.
Pakistan-based Jaish-e-Mohammad (JeM) has claimed responsibility for the terror attack in Jammu and Kashmir's Pulwama district on Thursday that left at least 40 CRPF soldiers dead and five others critically wounded.
"The United States calls on Pakistan to end immediately the support and safe haven provided to all terrorist groups operating on its soil, whose only goal is to sow chaos, violence, and terror in the region," White House Press Secretary Sarah Sanders said in a late night statement on Thursday.
Bolton telephoned Doval Friday morning to express his condolences for the terror attack in Jammu and Kashmir and offered the US' full support to India in confronting terrorism.