Mattis applauded India's efforts to promote stability in the South Asia region, said Pentagon Spokesperson
Trump's trip to Brussels would be his first overseas visit after he was sworn-in.
Haley said her India visit aimed at solidifying partnership.
Mattis said the Trump administration is being very clear and firm in what it expects from Pakistan.
External Affairs Minister Sushma Swaraj and her American counterpart Mike Pompeo have agreed to reschedule the postponed '2+2 dialogue'.
General Mattis has been the most steadfast champion in Trump's cabinet of the US-India defence relationship. If Trump chooses a more pliable successor, the Pentagon's attention could go off India.
The US' strong assertion comes days after President Donald Trump pledged to answer further aggression from North Korea with "fire and fury".
The issues that figured prominently in these discussions included terrorism, Afghanistan and the situation in the Asia Pacific region.
>Putin's last-minute intervention with PM salvages $5.43 bn pact.
'Two powerful men shaking hands with two powerful women as equals. This photograph made me very happy,' says Aakar Patel.
'The biggest challenge Swaraj and Sitharaman will face is how far they can take their counterparts Pompeo and Mattis seriously.' 'One just doesn't know how long they will even keep their jobs.' 'They are basically salesmen peddling American wares.' 'Actually, there is nothing like 'American policies' in the Trump era,' says Ambassador M K Bhadrakumar.
America had postponed the much-awaited dialogue due to "unavoidable reasons" last month.
'India, he announced, is a "free, open, inclusive region" committed to the "common pursuit of progress and prosperity".' 'Prosperity yes. But free? Open?' 'Ask the Dalit tanner, the Muslim butcher, the Christian priest who writes pastoral letters.' 'Ask cattle traders of any religion or a Delhiwallah who enjoys a juicy steak.' 'Ask a Muslim who falls in love with a Hindu or vice versa,' says Sunanda K Datta-Ray.
Defence Secretary Mattis said he cannot certify that Islamabad has taken 'sufficient actions' against the dreaded Haqqani terror network.
Defence Minister Manohar Parrikar and outgoing United States Defence Secretary Ashton Carter on Thursday finalised the "major defence partner" status to India which will fast-track cooperation and sharing of high-end American defence technology.
During the election campaign Trump had said Clinton would be in jail if he won the elections. He now faces the consternation of supporters who took that pledge literally.
'China's military is expected to deploy full throttle its new equipment including J-20 stealth fighters, drones, medium range missile systems, surveillance and others to continue to put psychological pressure on India,' warns Srikanth Kondapalli, Professor in Chinese Studies, JNU.
Trump said he wants to move US immigration to a "merit- based system" and not allow immigrants to bring their extended families.
Trump attended his first address to the annual National Prayer Breakfast on Thursday.
The President has maintained that he has nothing to do with Russia.
The order also prevents all persons from Iraq, Syria, Iran, Sudan, Libya, Somalia or Yemen from entering the country for 30 days.
Since the change in administration in the US, Indian leaders have publicly and privately identified with American objectives in Afghanistan.
'I am hopeful that you will see more focused attention on this relationship,' former US assistant secretary of state Nisha Desai Biswal tells Alokananda Chakraborty.
"This will be the first dinner for a foreign dignitary at the White House under this administration. So, we think that's very significant," a senior administration official told reporters at the White House on the eve of Modi's arrival.
Even before assuming the United States President's office, Donald Trump has boasted about his election victory, his re-election prospects, re-prided himself for picking a "great" Cabinet and showered confidence on the capabilities of his son-in-law to broker peace in the volatile Middle East.
Rajeev Srinivasan on why there is the strong possibility that this whole thing is an elaborate charade and how the mainstream might have just played into Trump's showman hands.
Pakistan Prime Minister Shahid Khaqan Abbasi assured the Secretary of State that his country is committed to the war against terrorism.
When Obama signs the NDAA 2017 into law this week, the US-India partnership will be enshrined in US legislation, binding every succeeding administration, whatever its inclinations, to treat India as a 'major defence partner,' says Ajai Shukla.
'If push comes to shove, Pakistan does have the capability to make it difficult for the US and NATO forces to make even a withdrawal of troops out of Afghanistan in orderly fashion,' says Ambassador M K Bhadrakumar.
We see none of the euphoric build-up customary to India's encounter with US presidents in recent times. This gives Modi wriggle room to work on the much-needed reset of India-US ties.
'Trump's stated strong stance against Islamist extremism and terrorism could play into the Indo-US relationship.' 'It could mould US attitude and exert pressure on Pakistan.' 'In the event of US military presence in Afghanistan increasing, however, Pakistan could gain an opportunity to again emphasise its importance.'
US President Donald Trump triumphantly greeted supporters at the first of the three inaugural balls, joining his First Lady on stage to tell them: 'We did it."
'China was the elephant in the Oval Office and Trump would have sensed that Modi's foreign policy architecture has become disoriented sans the US' pivot to Asia,' points out Ambassador M K Bhadrakumar.
Here's why Rajeev Srinivasan believes there will be nothing particularly positive about the prime minister's US visit.
US defence secy James Mattis said that Syria will pay a 'very, very stiff price' if it used chemical weapons again.
Will the unpredictable North Korean leader provoke conflict on the Korean peninsula?
'This is the first time that the Americans have agreed to refer to "cross-border terrorist attacks" in a joint statement.' 'No wonder Pakistan has called the joint statement "singularly unhelpful" and has blasted it, and its all-weather friend China has applauded Pakistan's frontline role in combating terrorism,' points out former foreign secretary Ambassador Kanwal Sibal.
'If the US-Pakistan relationship continues to suffer, Pakistan may feel it has less to lose and decide that it need not keep a leash on LeT in order to appease America.' 'A tougher US policy toward Pakistan could lead to an emboldened and strengthened LeT and JeM, resulting in more terrorist attacks in India.'
Aziz Haniffa, who has covered every Indian Prime Minister's visit to the US since Rajiv Gandhi in 1985, gives us a peek into what's happening in Washington, DC on the eve of the Modi-Trump summit.
Incoming US President Donald Trump has assembled a core team that is -- not surprisingly -- overwhelmingly white and male.