President Donald Trump hit back at the wave of lawmakers in both parties opposed to his tariff policy Wednesday, slamming them as "weak" and urging everyone to "be cool" as he negotiates new trade deals with other countries.

"Every time I see a weak politician asking to stop Trade talks or the use of Tariffs to counter unfair Tariffs, I wonder, what can they be thinking? Are we just going to continue and let our farmers and country get ripped off?" Trump tweeted. "Lost $817 Billion on Trade last year. No weakness!"

He added, "When you have people snipping at your heels during a negotiation, it will only take longer to make a deal, and the deal will never be as good as it could have been with unity."

"Negotiations are going really well, be cool. The end result will be worth it!" Trump wrote.

Every time I see a weak politician asking to stop Trade talks or the use of Tariffs to counter unfair Tariffs, I wonder, what can they be thinking? Are we just going to continue and let our farmers and country get ripped off? Lost $817 Billion on Trade last year. No weakness! — Donald J. Trump (@realDonaldTrump) July 25, 2018

When you have people snipping at your heels during a negotiation, it will only take longer to make a deal, and the deal will never be as good as it could have been with unity. Negotiations are going really well, be cool. The end result will be worth it! — Donald J. Trump (@realDonaldTrump) July 25, 2018

China is targeting our farmers, who they know I love & respect, as a way of getting me to continue allowing them to take advantage of the U.S. They are being vicious in what will be their failed attempt. We were being nice - until now! China made $517 Billion on us last year. — Donald J. Trump (@realDonaldTrump) July 25, 2018

Trump went on the attack one day after Republicans on Capitol Hill lashed out against the Trump administration's new plan to help farmers hurt by the ongoing trade wars that have shut them out of international markets. On Tuesday, the Department of Agriculture announced it would dole out up to $12 billion in "temporary relief" to struggling farmers who have been hurt by Trump's tariffs.

The program prompted a wave of lawmakers to blast Trump not only for the announcement, but for the tariffs the White House had announced in recent months that led to retaliatory tariffs from other nations that have harmed farmers and U.S. consumers.

In March, after Trump announced a 25 percent tariff on steel imports and 10 percent tariff on aluminum imports from China, pork producers in the U.S. were hit with a retaliatory 25 percent tariff on their China-bound exports. Trump expanded tariffs to products from Mexico, Canada, and the E.U. in the months after that, prompting those countries, too, to implement retaliatory tariffs placed on U.S. exports.

China has since increased its tariff on U.S. pork exports to 50 percent, and Mexico imposed its own 20 percent tariff on U.S. pork. While Mexico left American corn off of their list of goods with tariffs, both the E.U. and China levied an additional 25 percent tariff on the crop.

Those tariffs have caused corn farmers and pork producers, in particular, to take huge financial hits. Markets for both have seen a roughly 15 percent drop in prices since the spring when Trump slapped his first tariffs on imported steel and aluminum from overseas.