* US officials set aggressive tone
* Deliver riposte to concerns about protectionism
* Say more America First steps to come
* Ross sees "inappropriate behaviour" by trade partners (Adds quote on weaker U.S. dollar)
DAVOS, Switzerland, Jan 24 (Reuters) - Senior U.S. officials hit back on Wednesday against suggestions that Donald Trump's "America First" agenda was hurting globalization and trade, setting an aggressive tone ahead of the U.S. president's visit to the World Economic Forum.
In keeping with Trump's combative trade stance, U.S. Treasury Secretary Steven Mnuchin also welcomed a weaker U.S. dollar, helping to send the world's reserve currency to a three-year low against a basket of major peers.
"Obviously a weaker dollar is good for us as it relates to trade and opportunities," Mnuchin told a press briefing at the annual summit in the Swiss ski resort of Davos.
World leaders, including Indian Prime Minister Narendra Modi, Canadas Justin Trudeau and Brazilian President Michel Temer, raised concerns this week at the summit about growing protectionism, in remarks that delegates said seemed aimed at Trumps policies.
German Chancellor Angela Merkel and French President Emmanuel Macron are also expected to speak later on Wednesday.
Under his America First agenda, Trump has threatened to withdraw from the North American free-trade agreement (NAFTA), disavowed the global climate change accord and criticized global institutions including the United Nations and NATO.
Trump is expected to arrive by Thursday and deliver a keynote address to the forum on Friday, mingling with the same elite "globalists" that he bashed during his 2016 presidential run.
Mnuchin and U.S. Commerce Secretary Wilbur Ross mounted a joint defence of Washington's aggressive trade actions in Davos on Wednesday and said more were to come.
"This is about an America First agenda. But America First does mean working with the rest of the world," Mnuchin said. "It just means that President Trump is looking out for American workers and American interests no different than he expects other leaders would look out for their own."
Ross said U.S. trade actions were provoked by "inappropriate behaviour on the part of our trading counterparties."
On Tuesday, for example, the United States slapped steep import tariffs on washing machines and solar panels, in moves billed as a way to protect American jobs. China and South Korea condemned the tariffs, with Seoul set to complain to the World Trade Organization over the "excessive" move.
"Many countries are very good at the rhetoric of free trade but in fact actually practice extreme protectionism," Ross said.
The slide in the dollar also helps U.S. exports, but Mnuchin noted: "Longer term the strength of the dollar is a reflection of the strength of the U.S. economy and the fact that it is and it continues to be the primary currency in terms of the reserve currency."
Many in Davos worry that a brighter world economic outlook could darken if geopolitical threats - from protectionism and climate change to cyber attacks and war - gather pace in 2018.
Trump, the first sitting U.S. president to attend the forum since Bill Clinton in 2000, is a source of much of this anxiety after a volatile first year in office in which he has turned American foreign policy on its head.
The U.S. delegation is the largest ever to come to Davos, with 10 members of the Trump's cabinet and senior White House staff, Mnuchin said. That includes Jared Kushner, Trump's son-in-law and adviser.
When asked about a new agreement that is expected among 11 countries to forge an Asia-Pacific trade pact after the United States pulled out of an earlier version, Mnuchin said the Americans' involvement was "not off the table".
But he added, "We are fans of bilateral trading agreements."
Earlier on Tuesday, Canada's Trudeau called the new trade agreement, expected to be signed in Chile in March, the "right deal".
Ross said Trudeaus comments needed to be taken in the context of the latest round of talks on NAFTA. Perhaps there was some inclination to use that to "put pressure on the U.S. in the NAFTA talks," Ross said. (Reporting by Paritosh Bansal; Editing by Mark Bendeich, William Maclean)