The United States on Monday said countries trading with North Korea were aiding its "dangerous nuclear intentions" as the United Nations Security Council mulled tough new sanctions and the isolated regime showed signs of planning more missile tests.
South Korea said it was talking to Washington about deploying aircraft carriers and strategic bombers to the Korean peninsula following the North's sixth and most powerful nuclear test on Sunday.
South Korean President Moon Jae-in and U.S. President Donald Trump agreed in a telephone call to scrap a warhead weight limit on South Korea's missiles, South Korea's presidential office said, enabling it to strike North Korea with greater force in the event of a military conflict.
Trump also spoke with German Chancellor Angela Merkel over the telephone, reiterating that "all options" to address the threat are on the table. In a statement, the White House said the two leaders condemned North Korea's nuclear test and reaffirmed the importance of close coordination at the United Nations.
A statement from the German government also said Merkel agreed to push the European Union for tougher sanctions against North Korea.
At a Security Council meeting, U.S. Ambassador Nikki Haley said North Korea's Kim Jong Un was "begging for war" and urged the 15-member group to adopt the strongest possible measures to deter him.
"War is never something the United States wants. We don't want it now. But our country's patience is not unlimited. We will defend our allies and our territory," Haley said.
"The United States will look at every country that does business with North Korea as a country that is giving aid to their reckless and dangerous nuclear intentions," she said.
Haley said the United States will circulate a new Security Council resolution on North Korea this week and wants a vote on it next Monday.
China, a top trading partner with North Korea, and Russia called for a peaceful resolution to the crisis.
"China will never allow chaos and war on the (Korean) Peninsula," said Liu Jieyi, the Chinese ambassador to the United Nations.
Russia said peace in the region was in jeopardy.
"A comprehensive settlement to the nuclear and other issues plaguing the Korean peninsula can be arrived at solely through political diplomatic channels," Russia's U.N. Ambassador Vassily
North Korea has been under U.N. sanctions since 2006 over its ballistic missile and nuclear programs. Typically, China and Russia only view a test of a long-range missile or a nuclear
weapon as a trigger for further possible U.N. sanctions.
Trump had asked to be briefed on all available military options, according to his defense chief.
Officials said activity around missile launch sites suggested North Korea planned more missile tests.
"We have continued to see signs of possibly more ballistic missile launches. We also forecast North Korea could fire an intercontinental ballistic missile," Jang Kyoung-soo, acting deputy minister of national defense policy, told a parliament hearing on Monday.
North Korea tested two ICBMs in July that could fly about 10,000 km (6,200 miles), putting many parts of the U.S. mainland within range and prompting a new round of tough international sanctions.