NEW YORK, Sept 21 (Reuters) - U.S. President Donald Trump ordered new sanctions on Thursday that open the door wider to blacklisting people and entities doing business with North Korea, including its shipping and trade networks, further tightening the screws on Pyongyangs nuclear and missile program.

Trump stopped short of going after North Koreas biggest trading partner, China, and praised its central bank for ordering Chinese banks to stop doing business with North Korea.

The additional sanctions on Pyongyang showed that Trump was giving more time for economic pressures to weigh on North Korea after warning about the possibility of military action earlier in the week in his first speech to the United Nations.

Asked ahead of a lunch meeting with the leaders of Japan and South Korea if diplomacy was still possible, Trump nodded his head and said, Why not?

North Korea has launched dozens of missiles under Kim Jong Uns leadership as it accelerates a weapons program designed to give it the ability to target the United States with a powerful, nuclear-tipped missile.

Resisting intensifying international pressure, Pyongyang conducted its sixth and largest nuclear test on Sept. 3, and launched numerous missiles this year, including two intercontinental ballistic missiles and two other rockets that flew over Japan.

Today Im announcing a new executive order, just signed, that significantly expands our authority to target individual companies, financial institutions, that finance and facilitate trade with North Korea, Trump told reporters.

Our new executive order will cut off sources of revenue that fund North Koreas efforts to develop the deadliest weapons known to humankind.

Trump said North Koreas textiles, fishing, information technology, and manufacturing industries were among those the United States could target.

He said the order enhanced the U.S. Treasury Departments authority to target those that conduct significant trade in goods, services or technology with North Korea.

For much too long North Korea has been allowed to abuse the international financial system to facilitate funding its nuclear and missile programs, Trump said.

Trump did not mention Pyongyangs oil trade. Four sources told Reuters Chinas central bank has told banks to strictly implement United Nations sanctions against North Korea.

The U.N. Security Council has unanimously imposed nine rounds of sanctions on North Koreasince 2006, the latest earlier this month capping fuel supplies to the isolated state.

European Union ambassadors have reached an initial agreement to impose more economic sanctions on North Korea, going beyond the latest round of U.N, measures, officials and diplomats said.

Trump warned the North Korean leader in his U.N. address on Tuesday that the United States, if threatened, would totally destroy his country of 26 million people.

It was Trumps most direct military threat to attack North Korea and his latest expression of concern about Pyongyangs repeated launching of ballistic missiles over Japan and underground nuclear tests.

North Koreas foreign minister likened Trump to a barking dog in response.

South Korean President Moon Jae-in, who met with Trump on Thursday and addressed the U.N. General Assembly, said sanctions were needed to bring Pyongyang to the negotiating table and force it to give up its nuclear weapons, but Seoul was not seeking North Koreas collapse.

All of our endeavors are to prevent war from breaking out and maintain peace, Moon said in his speech. He warned the nuclear issue had to be managed stably so that accidental military clashes will not destroy peace.

U.S. Treasury Secretary Steven Mnuchin will hold a news briefing at 3 p.m. (1900 GMT) in which he is expected to discuss the Trump administrations sanctions announcement.

In Geneva, North Korea told a U.N. rights panel that international sanctions would endanger the survival of North Korean children.

AID PLAN

Anthony Ruggiero, with the Foundation for Defense of Democracies think tank, said Trumps order would force banks and firms to choose between North Korea and the United States.

This approach worked with Iran as companies, banks, governments, and individuals chose the United States, and likely will restrict North Koreas revenue, Ruggiero said.

South Korea approved a plan on Thursday to send $8 million worth of aid to North Korea, as China warned the crisis on the Korean peninsula was getting more serious by the day.

The United States and South Korea are technically still at war with North Korea because the 1950-53 Korean conflict ended with a truce and not a peace treaty. The North accuses the United States, which has 28,500 troops in South Korea, of planning to invade and regularly threatens to destroy it and its Asian allies.

Mnuchin has warned China that if it did not follow through on new U.N. sanctions on the North Koreans, Washington would put additional sanctions on them and prevent them from accessing the U.S. and international dollar system.

Last month, the Trump administration blacklisted 16 Chinese, Russian and Singaporean companies and people for trading with banned North Korean entities, including in coal, oil and metals.

On Wednesday, U.S. Secretary of State Rex Tillerson said there were some indications that sanctions were beginning to cause fuel shortages in North Korea.

(Reporting by Steve Holland and David Brunnstrom; additional reporting by Michelle Nichols in New York and Susan Heavey, Doina Chiacu, Eric Walsh and Tim Ahmann in Washington, Robin Emmott in Brussels; Writing by Yara Bayoumy; Editing by Grant McCool)