Trump acted to ban officials from lobbying the US on behalf of foreign government after he'd previously hired Ukraine lobbyist Paul Manafort to chair his campaign

Donald Trump acted Saturday to fulfill a key portion of his pledge to 'drain the swamp' in Washington, banning administration officials from ever lobbying the US on behalf of a foreign government and imposing a separate five-year ban on other lobbying.

Trump has said individuals who want to aid him in his 'quest' to 'Make America Great Again' should focus on the jobs they will be doing to help the American people, not thinking ahead to the future income they could rake in by peddling their influence after serving in government.

'Most of the people standing behind me will not be able to go to work,' Trump joked, referring to an array of White House officials who lined up behind him as he sat at his Oval Office desk.

Trump hopes to 'drain the swamp' in Washington in part by banning administration officials from every lobbying the US on behalf of a foreign government and imposing a separate 5-year ban on other lobbying

His former campaign chairman Paul Manafort resigned on August 18 in the wake of campaign shake-up and revelations about his work in Ukraine

The officials included Vice President Mike Pence, chief of staff Reince Priebus, senior strategist Steve Bannon and counselor Kellyanne Conway.

He added: 'So you have one last chance to get out.'

Trump said he talked about the ban a lot during the campaign and 'we're now putting it into effect.'

But Trump's efforts to 'drain the swamp' sometimes meant his corrupt campaign staff had to be drained.

His former campaign chairman Paul Manafort resigned on August 18 in the wake of campaign shake-up and revelations about his work in Ukraine.

Manafort's resignation in August came a day after The Associated Press reported that confidential emails from Manafort's firm contradicted his claims that he had never lobbied on behalf of Ukrainian political figures in the US.

Emails between Manafort's deputy, Rick Gates, also a top Trump adviser, and the lobbying firm Mercury LLC had shown that Manafort's firm, DMP International LLC, directly orchestrated a covert Washington lobbying operation on behalf of Ukraine's then-ruling political party.

Manafort's resignation came after the revelation of confidential emails that showed he'd lobbied on behalf of Ukrainian political figures in the US

The effort included not just legislative outreach but also attempts to sway American public opinion and gather political intelligence on competing lobbying efforts in the U.S.

The emails obtained by the Associated Press did not describe details about the role of Manafort, Gates' boss at the firm.

But current and former employees at Mercury and a second lobbying firm, the Podesta Group, some of whom spoke on condition of anonymity because they are subject to non-disclosure agreements said that Manafort oversaw the lobbying efforts and spoke by phone about them.

Manafort and Gates never registered as foreign agents for their work as required under federal law.

The usual suspects: Steven Bannon and Kellyanne Conway were with Trump when he signed the order

Trump said those who want to 'Make America Great Again' should focus on the jobs they will be doing to help the Americans, not thinking ahead to their future paychecks

In a pair of separate actions, Trump took steps to begin restructuring the White House National Security Council and the Homeland Security Council.

He also gave Defense Secretary Jim Mattis and the Joint Chiefs of Staff, the president's top military advisers, 30 days to come up with a plan defeat the Islamic State group.

Scores of people have been killed in terrorist acts that IS has carried out overseas or has inspired on US soil.

Under an executive order that Trump signed in the presence of the news media, every political appointee joining the executive branch on or after January 20 - the day Trump took office - must agree to the lobbying bans.

That includes avoiding, for five years after leaving, lobbying the agency they worked for.

Another provision sets a two-year period during which appointees must avoid working on issues involving former employers or clients.

Trump is allowed to waive any of the restrictions.

In a pair of separate actions, Trump took steps to begin restructuring the White House National Security Council and the Homeland Security Council

He also gave Defense Secretary Jim Mattis and the Joint Chiefs of Staff, the president's top military advisers, 30 days to come up with a plan defeat the Islamic State group. Pictured: Reince Priebus and Steve Bannon

Questions had been raised about how the bans would be enforced.

The order says they are 'solely enforceable' by the US government 'by any legally available means,' including debarment proceeding within any affected executive branch agency, or civil court proceedings.

Former appointees who are found to have violated the ban may also be barred from lobbying their former agency for up to five years, on top of the five-year period covered by the pledge, the executive order states.

Trump said the order supersedes one that President Barack Obama signed on January 21, 2009, that banned anyone from lobbying the government for a period of two years after leaving.

Trump said Obama's order was 'full of loopholes.'

The president signed the order and a pair of presidential memoranda near the end of an intense day of telephone diplomacy during which he discussed a range of issues with the leaders of Japan, Germany, Russia, France and Australia.

All are leaders Trump needs to build relationships with.

Trump had released the plan for a lobbying ban a few weeks before the November election, one of several promised policies aimed at curbing corruption and the influence of lobbyists in Washington.

Trump also made promises about transparency and ethics.

Some have argued that the ban could make it difficult for Trump to fill thousands of jobs throughout the administration by causing some candidates to become squeamish about limiting their ability to make money after they leave government employment.

Others say the prohibitions on lobbying are too insignificant to be effective.