SAO PAULO - US proposal to slap 50 percent tariffs on imports from Brazil could trigger Brazil's Reciprocity Law, President Luiz Inacio Lula da Silva said Thursday.

Lula said that if the 50 percent tariff takes effect on Aug 1 as announced, his government will enforce the law while keeping negotiations open.

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"But if there is no negotiation, the Reciprocity Law will apply. If he charges us 50 percent, we will charge him 50 percent," Lula told local television network RecordTV.

Brazil has run a trade deficit with the United States (US), its second-largest trade partner, for the past 15 years, Lula said.