Esper said that the international rules-based order that America and its allies had worked hard to establish was being tested in new and precarious ways.
A senior US diplomat said that the service-to-service inter-operability is going to continue to grow as the two countries continue work towards concluding outstanding defence enabling agreements.
Mark Esper has said that two fighter squadrons and additional missile defence batteries were being sent to Saudi Arabia, bringing to about 3,000 the total number of troops deployed to the kingdom.
According to Defense Secretary Mark Esper, US forces will remain in contact with Turkey and Syrian Kurdish fighters that were allies of the US in the fight against IS.
Esper's reassurance came despite the White House announcing that it would not cooperate with the Democratic-led House of Representatives.
Discussed with Rajnath Singh future steps needed for working together more closely: US Defence Secretary
Defence Minister Rajnath Singh said Esper told him that the abrogation of provisions of Article 370 was an internal matter of India.
Since former Secretary of Defence James Mattis' resignation last December, the Pentagon has undergone the longest without a formal head in history.