(CNN) Democrats are warning that President Donald Trump has a credibility problem as his administration grapples with the prospect of a new North Korean nuclear test.

They're pointing to the miscommunication over the aircraft carrier USS Carl Vinson and accusing the Trump administration of lacking any strategy for responding to North Korea.

"I think they have a big credibility problem," Massachusetts Democrat Sen. Ed Markey told CNN's Jake Tapper. "They obviously had no idea where this aircraft carrier fleet was going, or they did know and they decided to lie about the fact that it wasn't heading toward North Korea. Either way, if you're an ally of the United States, you're just wondering, what's going on inside of their administration?"

Rep. Ruben Gallego, an Arizona Democrat and House Armed Services member, tweeted : "If the President can lose track of a 100,000 ton aircraft carrier, how well is he managing the rest of the US government?"

But Republicans are defending Trump's handling of North Korea and his efforts to press China to stop Pyongyang's nuclear weapons development.

House Foreign Affairs Chairman Ed Royce suggested the Trump administration's actions, including Trump's statement that an "armada" was headed to the Korean Peninsula, helped deter or delay North Korea's latest nuclear test.

"It would have been their sixth test. And there was considerable communication sent their way on this issue," the California Republican told CNN's Wolf Blitzer. "Now, I guess we will never know whether or not part of what they responded to was the message that a carrier group was headed to the region."

The partisan divide is the latest fighting on Capitol Hill over the Trump administration's foreign policy, as Trump's actions in Yemen, Syria and Afghanistan have all sparked Democratic criticisms as well as some from Republicans.

Trump has said he's pushing Chinese President Xi Jinping to take a harder line toward North Korea after the two met earlier this month. Vice President Mike Pence traveled to South Korea this week, telling CNN the Trump administration would "abandon the failed policy of strategic patience."

And Pence's stop at the DMZ, the demilitarized zone between the North and South, was praised by Republicans as sending an important message.

"The fact that the vice president goes to the DMZ and looks across the border and says to the North Koreans, 'We're not going to allow you to get a missile to hit our homeland' is pretty striking," Sen. Lindsey Graham, a South Carolina Republican, said on NBC's "Today."

Graham added that he was confident Trump could convince China to act, too.

"China can stop it if they want. If they don't, I think President Trump will," Graham said. "I hope they're listening in North Korea."

To Democrats, however, the Trump administration has failed to articulate a clear strategy to deter North Korea.

"It's been less than 100 days and our secretary of state has basically said he's going to stop talking about North Korea," Rep. Ted Lieu, a California Democrat, told Blitzer. "That shows to me that they have not tried very hard nor understood the potentially catastrophic consequences of what a military solution might mean."

And Sen. Ben Cardin of Maryland, the top Democrat on the Senate Foreign Relations Committee, raised questions over whether Trump really knows his own strategy.

"I'm not asking the President to telegraph his actions to the North Koreans," Cardin said on CNN's "Erin Burnett OutFront" earlier this week. "I am asking him to confer with us, the Congress of the United States, so that we're all together on this. Our concern is that we don't know if he knows what his policy is in regard to North Korea."