In a speech to an international relations conference, Murdoch said defeat of the US-Colombia free trade deal "would be taken as another sign that the US will not stand by its friends when the going gets tough."
"We need to make clear to the leadership in Congress ... what killing this trade deal would mean," Murdoch said in prepared remarks.
Colombia already has duty-free access to the US market for most of its goods under a US trade preference program that dates back to 1991.
The Colombia free trade pact would immediately eliminate many tariffs on US businesses that export to Colombia and phase out the rest.
Murdoch's remarks were similar to comments made last week by President George W. Bush, who complained that House Democrats had voted to indefinitely delay action on the pact.
Many Democrats say that Colombia remains too dangerous a place for trade unionists, despite the progress Uribe has made. They want the government to do more to stop killings and put murderers in jail before Congress votes on the pact.
House Speaker Nancy Pelosi said it was still possible the House could vote this year on the deal if more pressing domestic economic concerns were addressed first.
In his remarks, Murdoch argued that moving ahead with the Colombia free trade pact would help American businesses while giving "strong moral support" to Colombian President Alvaro Uribe as the country struggles with poverty, drug lords and terrorists.
Murdoch also backed the expansion of NATO and criticized European countries, who he said were not shouldering their share of the burden of battling insurgents in Afghanistan.
"We must face up to a painful truth: Europe no longer has either the political will or social culture to support military engagements in defense of itself and its allies," Murdoch said in his remarks.
Murdoch said the invitation of Albania and Croatia to join NATO was "a welcome start."
"Expansion is the only hope of invigorating an alliance weighed down by those who are no longer willing to commit themselves to defend its founding principles," Murdoch said. (Reuters)
