President Trump suggested on Twitter another possible response to North Korea's sixth and most powerful nuclear test just moments after saying "we'll see" in response to a shouted question about attacking the dictatorship.

"The United States is considering, in addition to other options, stopping all trade with any country doing business with North Korea," Trump tweeted.

The president indicated he will discuss options with White House Chief of Staff John Kelly and Defense Secretary Jim Mattis.

"I will be meeting General Kelly, General Mattis and other military leaders at the White House to discuss North Korea. Thank you," Trump tweeted.

Adding pressure to China and Russia to impose severe economic penalties on North Korea was suggested by many lawmakers Sunday morning.

"We're not going all out in terms of secondary sanctions," said Texas Rep. Joaquin Castro, a Democrat.