The US president was addressing reporters during his holiday at his New Jersey golf club before a security briefing with top advisers.
"We are improving our readiness not only in the air, but as a logistical support team", Col. R. Scott Jobe, the 35th Fighter Wing commander, said in a statement.
North Korea has been responding through state media by indicating that military is about to present a plan to Kim jong-Un to strike near Guam with missiles by the end of this month, a threat that has ratcheted up concerns within the Trump administration. "The more we threaten, the worse the situation is going to get", Jenny Town, assistant director of the U.S. -Korea Institute at Johns Hopkins School of Advanced International Studies, told USA Today.
But he declined to say whether the United States was considering a pre-emptive military strike, arguing that his administration never discusses such deliberations publicly. "They didn't want to take on the issue and I have no choice but to take it on, and I'm taking it on".
Mr Trump said it was time that somebody stood up to the pariah nation.
Of the negotiations, Trump said, "We'll either be very, very successful quickly or we're going to be very, very successful in a different way, quickly".
Mr Trump said the USA "of course" would always consider negotiations with North Korea, but added that negotiations with the North have failed for the last 25 years.
United States President Donald Trump has reiterated his bellicose rhetoric on North Korea and warned Kim Jong Un that if any of the US territory is attacked, he "will truly regret it".
Then came Friday morning's Twitter post, in which Trump - who responded to criticism calling "fire and fury" comments inflammatory by suggesting they perhaps had not gone far enough - said the USA was "locked and loaded".
"Things will happen to them like they never thought possible, OK?"