The President previously criticised the Obama Administration for telegraphing its military moves in advance.
When Trump says "smart" missiles, he means missiles that use precision guidance systems based on lasers or satellite-powered GPS to pinpoint and strike targets with exactitude.
The US military has been using so many precision-guided munitions in the fight against Isis in recent years that the Pentagon had to work with defence contractors to step up the weapons' production and introduce new types of missiles to the fight.
The military can also fasten "smart" guidance kits on existing "dumb" missiles to outfit them with the capability to hit specific targets.
The Pentagon has long criticised Russia for using so-called "dumb bombs," or weapons that lack precision guidance technology, while striking targets in Syria.
Missiles without precision guidance are far cheaper and in large supply in Russia's arsenal but have a poorer track record of hitting specific targets and therefore cause more collateral damage.
Former Secretary of Defence Ash Carter, speaking in Senate testimony in late 2015, said at the time that the vast majority of Russia's strikes in Syria, some 85 to 90 per cent, "use dumb bombs, which obviously increases the possibility of civilian casualties."
Trump launched 59 Tomahawk cruise missiles at a Syrian military airfield in April 2017 in retaliation for a chemical attack.
The military action marked the first direct American assault on Assad's Government. The Pentagon otherwise has limited its involvement in Syria to defeating Isis primarily through local proxy forces.
The United States gave Russia advance warning before the strike last year.
Tomahawk cruise missiles, first used by the US military during Desert Storm, maneouver easily and fly low to hit targets. They can be reprogrammed mid-flight to hit different GPS coordinates.
